Crystal structure and substrate recognition mechanism of the prolyl endoprotease PEP from Aspergillus niger.

Proteases are enzymes that are not only essential for life but also industrially important. Understanding the substrate recognition mechanisms of proteases is important to enhance the use of proteases. The fungus Aspergillus produces a wide variety of proteases, including PEP, which is a prolyl endoprotease from A. niger. Although PEP exhibits amino acid sequence similarity to the serine peptidase family S28 proteins (PRCP and DPP7) that recognize Pro-X bonds in the terminal regions of peptides, PEP recognizes Pro-X bonds not only in peptides but also in proteins. To reveal the structural basis of the prolyl endoprotease activity of PEP, we determined the structure of PEP by X-ray crystallography at a resolution of 1.75 Å. The PEP structure shows that PEP has a wide-open catalytic pocket compared to its homologs. The characteristic catalytic pocket structure of PEP is predicted to be important for the recognition of protein substrates.

Comparison of attitudes, awareness, and perceptions regarding oral healthcare between dental and nursing students before and after oral healthcare education.

BACKGROUND: Oral healthcare education for health professional students is important to promote collaborative oral healthcare practice among health professionals. The purpose of this follow-up, cross-sectional study was to investigate attitudes, awareness, and perceptions regarding oral healthcare among dental and nursing students and to compare them both between baseline and the completion of the education programme and between dental and nursing students to identify problems with oral healthcare programmes in dental education. METHOD: The subjects included 88 dental and 119 nursing students. The dental students participated in geriatric and preventive dentistry courses for oral healthcare education. The nursing students participated in independent oral healthcare courses comprising 45 h of training with case-based learning and were taught and instructed by multiple health professionals, including dentists. Questionnaires were distributed to the participants to compare attitudes, awareness, and perceptions regarding oral healthcare between baseline and the completion of the education programme and between dental and nursing students. A chi-square test, Wilcoxon signed-rank test, and Mann-Whitney U test were used to compare the data. RESULT AND CONCLUSION: The data of 48 (28 male and 20 female) dental students and 103 (9 male and 94 female) nursing students who completed the questionnaires both at baseline and after the education programme were used for the comparisons. After the education programme, more than 90% of the students were interested in oral healthcare practice; hoped to practise oral healthcare post-qualification; and perceived oral healthcare to be effective for preventing dental caries, periodontal diseases, and aspiration pneumonia. These attitudes and perceptions were statistically significantly improved after the education. However, the level of awareness of oral healthcare and the level of perception of the importance of collaboration with healthcare workers in oral healthcare practice after education were lower in the dental students than in the nursing students. Multi-professional oral healthcare education with case-based learning has the potential to improve awareness of oral healthcare and perceptions of the importance of collaborative oral healthcare practice.

Associations of Oral Health-Related Quality of Life with age, oral status, and oral function among psychiatric inpatients in Japan: a cross-sectional study.

BACKGROUND: As the general population of Japan ages, the population of hospitalized psychiatric patients is also ageing. The purpose of this study was to investigate the associations of oral health-related quality of life (OHRQoL) with age and oral health, including oral and swallowing function, among psychiatric inpatients. METHODS: The subjects included 165 psychiatric inpatients in psychiatric hospitals in Japan. The General Oral Health Assessment Index (GOHAI) and the Eating Assessment Tool (EAT-10) were included in the questionnaire survey for the measurement of OHRQoL and the screening of dysphagia. A score ≥ 3 on the EAT-10 was defined as suspected dysphagia. Oral examinations and oral diadochokinesis (ODK) measurements for the tongue-lip motor function evaluation were conducted. The inpatients with acute psychiatric symptoms, moderate and severe dementia, and cognitive impairment that affected their ability to communicate and relate their feelings were excluded. A chi-squared test, the Mann-Whitney U test, and linear regression analysis were used for the analysis. The data were analysed at the 5% significance level. RESULTS: A total of 100 (64.5%) psychiatric inpatients (mean age, 67.3 [SD, 14.5] years, 49% males, and 51% females) participated in this study. The means ± SDs for the decayed missing filled teeth (DMFT) index and GOHAI score were 20.6 ± 6 and 49.7 ± 7.9, respectively. The GOHAI score in the older age group (≥ 65 years) was significantly lower than that in the younger age group (< 65 years). The mean ODK scores were less than 3 times/s for all syllables. The percentage of the participants with suspected dysphagia was 45.0%. Tooth loss and suspected dysphagia were significantly associated with low GOHAI scores. The EAT-10 score was significantly correlated with the GOHAI score only after adjusting for age and sex (ß = - 0.725, 95% CI - 0.97, - 0.64). CONCLUSIONS: In hospitalized psychiatric patients, impaired oral health in the older subjects was more pronounced compared with that among general adults. Tooth loss and swallowing function were associated with OHRQoL. Therefore, oral care for the recovery of occlusal and swallowing functions may be needed to improve OHRQoL among psychiatric patients.

Factors associated with nurses' performance of oral assessments and dental referrals for hospital inpatients.

BACKGROUND: Nurses' oral assessment and dental referral performance for inpatients are important to provide appropriate oral care services in hospitals. The purpose of this study was to investigate the knowledge, attitudes, and performance of oral assessments and dental referrals for their inpatients among nurses and to identify factors associated with that performance to promote oral health care in hospitals. METHODS: All nurses (n = 919) who worked at five hospitals in Japan were recruited as responders. A questionnaire regarding their performance of oral assessments and dental referrals was distributed to the subjects in each hospital. The data were collected from August 2018 to September 2018. RESULTS: A total of 757 (82.4%) nurses (82 males and 675 females) responded to the questionnaire. With respect to each of the 8 oral assessment categories, 16.2-41.2% of the nurses performed oral assessments for more than 50% of their inpatients, and 20.3-29.9% had encouraged more than one inpatient to see a dentist within the previous 3 months. Significant differences were found by ward and hospital in their performance of oral assessments for inpatients. Additionally, their oral assessment performance, knowledge of the usage of oral assessment tools, wards, and hospitals were significantly associated with their dental referral performance. CONCLUSIONS: The performance of oral assessment and dental referral was not developed sufficiently in the hospitals. Thus, oral health professionals should support oral assessment education for nurses, including usage of assessment tools, to promote dental referral by nurses. These results may contribute to promotion of dental referral performance by nurses and provision of oral health care by oral health professionals for hospital inpatients.

Association between subjective well-being and presence of primary care dentists in community-dwelling elderly people: A cross-sectional study.

OBJECTIVE: The aim was to investigate the relationships between subjective well-being and the existence of primary care dentists in community-dwelling elderly people. BACKGROUND: Some studies have reported subjective well-being focusing on oral health, but no studies have examined the relationship between subjective well-being and primary care dentists. METHODS: This cross-sectional study used data from community-dwelling elderly people aged ≥70 years (n = 624). The Philadelphia Geriatric Center Morale Scale (PGCMS; range = 0 [low morale]-17) was used to assess subjective well-being. Additional information regarding age group, sex, medical consulting situation (ambulatory care/home care), primary care dentists, family structure, economic status, health status was collected via questionnaire. RESULTS: The average PGCMS score in ambulatory care patients (ACP) group who have primary care dentists was highest among community-dwelling elderly people. In a logistic regression model, a low PGCMS score (0-11) was independently correlated to 80-89 age group (OR = 1.70; 95% CI, 1.13-2.54; P = 0.008), ≥90 age group (OR = 3.86; 95% CI, 1.83-8.18; P < 0.001), unsatisfied for economic status (OR = 2.68; 95% CI, 1.59-4.53; P < 0.001), unsatisfied for health status (OR = 3.94; 95% CI, 2.60-5.98; P < 0.001) and having no primary care dentists (OR = 1.81; 95% CI, 1.09-3.01; P = 0.021) in ACP group. CONCLUSIONS: The subjective well-being of ACP who have primary care dentists was higher than in other people. Primary dentists contributed to the subjective well-being of elderly people.

Practices, Attitudes, and Confidence of Nurses in the Performance of Oral Health Checkups for Elderly Patients in a Japanese Hospital.

PURPOSE: To investigate the practices, attitudes, and confidence of nurses in the performance of oral health checkups in order to develop an educational oral health checkup training programme for nurses. MATERIALS AND METHODS: A cross-sectional questionnaire survey was distributed to nurses (n = 184) who worked in a hospital and an affiliated long-term care facility in Japan from September to October in 2016. The questionnaire survey investigated their practices, attitudes and confidence in the performance of oral health checkups for elderly patients who were in their care and the factors that were associated with the performance of oral health checkups. RESULTS: A total of 143 (77.7%) nurses participated in this study. Almost half (51.7%) performed oral health checkups for elderly patients. More than 60% examined the lip, tongue and tongue coating, gingiva and oral mucosa, and oral cleanliness; however only 32.4% examined the present teeth and 8.1% examined the saliva. Approximately 90% of the nurses felt that all health professionals should perform oral health checkups for elderly patients who were in their care. Their confidence of the oral examination was statistically significantly associated with their performance of oral health checkups for elderly patients. CONCLUSIONS: This is the first survey to investigate the practices, attitudes, and confidence of nurses in the performance of oral health checkups. These findings will contribute to the development of a training programme for nurses who perform oral health checkups in elderly patients.

Structural basis of abscisic acid signalling.

The phytohormone abscisic acid (ABA) mediates the adaptation of plants to environmental stresses such as drought and regulates developmental signals such as seed maturation. Within plants, the PYR/PYL/RCAR family of START proteins receives ABA to inhibit the phosphatase activity of the group-A protein phosphatases 2C (PP2Cs), which are major negative regulators in ABA signalling. Here we present the crystal structures of the ABA receptor PYL1 bound with (+)-ABA, and the complex formed by the further binding of (+)-ABA-bound PYL1 with the PP2C protein ABI1. PYL1 binds (+)-ABA using the START-protein-specific ligand-binding site, thereby forming a hydrophobic pocket on the surface of the closed lid. (+)-ABA-bound PYL1 tightly interacts with a PP2C domain of ABI1 by using the hydrophobic pocket to cover the active site of ABI1 like a plug. Our results reveal the structural basis of the mechanism of (+)-ABA-dependent inhibition of ABI1 by PYL1 in ABA signalling.

[Perioperative Management of Elderly Patients Over 90 Years of Age with Femoral Neck/Trochanteric Fracture].

BACKGROUND: The use of anesthesia in patients older than 90 years has been increasing. We examined the perioperative management of these patients. METHODS: The perioperative complications, waiting period for surgery, method of anesthesia, and prognosis in patients older than 90 years undergoing operations for femoral neck/trochanteric fractures were retrospectively examined in our anesthesia database. RESULTS: The average age of patients was 94.0±2.8 years. All patients had preoperative complications, including hypertensive disease (91.7%), renal dysfunction, anemia, or dementia. The average waiting period for surgery was 3.7±2.1 days; 92.6% of the patients underwent surgery within 7 days and 40.7% within 2 days. The main reason for waiting was withdrawal of antiplatelet and anticoagulant drugs. Local anesthesia, including spinal and epidural anesthesia, was used in 77.8% of patients. General anesthesia was selected for those patients on hemodialysis and continuous antiplatelets/anticoagulants. Hypotension was observed in 63.0% of the patients. The postoperative course was satisfactory, with the exception of 2 patients who died within 3 months from pneumonia and heart failure, respectively. CONCLUSIONS: Anesthetic management of the patients was without major complications. Anesthesia, either general or local, was performed safely. Further study of the relative advantages of anesthetic methods is required.

Perioperative management of factor XI deficiency in a patient undergoing hip arthroplasty.

Factor XI deficiency, or hemophilia C, is a rare autosomal recessive bleeding disorder often diagnosed by inappropriate bleeding associated with trauma or a surgical procedure, and reports of anesthetic management of this disorder are rare. We experienced an 85-year-old man with femoral neck fracture who was diagnosed preoperatively with factor XI deficiency based on abnormally long activated partial thromboplastin time (APTT). He was scheduled for bipolar hip arthroplasty and was prepared for surgery by transfusion of fresh frozen plasma (FFP), instead of factor XI concentrates, which are not commercially available in Japan. Five units of FFP were transfused 6 days before surgery, and 10 units of FFP with 2 units of red concentrated cells (RCC) were used on the day of surgery. Transfusion of FFP shortened the APTT to a level sufficient to allow hemostasis, although not to within the normal range. Although the patient required transfusion of 2 units of RCC postoperatively, no bleeding complications occurred. For bipolar hip arthroplasty, transfusion of FFP produced sufficient hemostasis without the use of tranexamic acid, factor VII preparations, or desmopressin.

Molecular basis of Lys-63-linked polyubiquitination inhibition by the interaction between human deubiquitinating enzyme OTUB1 and ubiquitin-conjugating enzyme UBC13.

UBC13 is the only known E2 ubiquitin (Ub)-conjugating enzyme that produces Lys-63-linked Ub chain with its cofactor E2 variant UEV1a or MMS2. Lys-63-linked ubiquitination is crucial for recruitment of DNA repair and damage response molecules to sites of DNA double-strand breaks (DSBs). A deubiquitinating enzyme OTUB1 suppresses Lys-63-linked ubiquitination of chromatin surrounding DSBs by binding UBC13 to inhibit its E2 activity independently of the isopeptidase activity. OTUB1 strongly suppresses UBC13-dependent Lys-63-linked tri-Ub production, whereas it allows di-Ub production in vitro. The mechanism of this non-canonical OTUB1-mediated inhibition of ubiquitination remains to be elucidated. Furthermore, the atomic level information of the interaction between human OTUB1 and UBC13 has not been reported. Here, we determined the crystal structure of human OTUB1 in complex with human UBC13 and MMS2 at 3.15 Å resolution. The presented atomic-level interactions were confirmed by surface-plasmon resonance spectroscopy with structure-based mutagenesis. The designed OTUB1 mutants cannot inhibit Lys-63-linked Ub chain formation in vitro and histone ubiquitination and 53BP1 assembly around DSB sites in vivo. Finally, we propose a model for how capping of di-Ub by the OTUB1-UBC13-MMS2/UEV1a complex efficiently inhibits Lys-63-linked tri-Ub formation.

Current status and future prospects for oral care education in Bachelor of Nursing curriculums: A Japanese cross-sectional study.

OBJECTIVE: This study sought to investigate the current status and faculty members' perceptions of oral care education in Bachelor of Nursing curriculums in Japan. METHOD: Data were gathered through a questionnaire survey of 196 participants, who were faculty members in charge of oral care education in the basic, adult, gerontological, and home nursing fields, from 295 nursing schools that offered Bachelor degrees in nursing across Japan. RESULTS: The quantitative data showed that 38.5% of the participants worked for less than 5 years as oral care educators, only 15.5% taught oral care in perioperative wards, only 62.2% used an oral care training simulator, and less than 30% believed that training in the prevention of oral diseases should be enhanced. From the descriptive responses, this study identified such problems as the inability of students to perform student-on-student and patient-based oral care training owing to the risk of SARS-CoV-2 transmission, and the lack of teaching materials, time, and human resources, and cooperation with other nursing fields and health professionals. CONCLUSIONS: This study revealed several problems in oral care education in the Bachelor of Nursing curriculums in Japan. To tackle these challenges, this study suggests the development of an interdisciplinary course that unifies oral care education in nursing fields, in order to promote collaborative oral care education and to improve nursing students' knowledge and skills of oral care.

A Survey of Oral Assessment and Healthcare Education at Nursing Schools in Japan.

OBJECTIVES: This study aimed to investigate the performance of oral assessment and health care education at nursing schools across Japan to identify problems and the need for oral health professional support. METHODS: The participants were the academic staff in charge of oral health care education in the basic, adult, gerontological, and home nursing fields of 295 schools in Japan that offered a bachelor's degree in nursing. A questionnaire was sent to 1180 heads of the nursing fields of these schools. They were requested to have oral health care educators complete the survey; data on the performance of oral assessment and health care education and human resources allocated were collected through a questionnaire. RESULTS: A total of 311 (26%) questionnaires were returned, 196 (63%) of which were completed by oral health care educators. Regarding the performance of oral assessment education, the majority (71%) of them spent less than 2 hours in teaching, and only 24.5% taught the usage of oral assessment tools. Regarding the performance of oral health care education, more than 90% spent less than 2 hours in lecture-based and practical oral health care education, respectively. Less than half taught the association of periodontal diseases with diabetes and cardiovascular diseases and use of fluoride for caries prevention in the lectures, and only approximately 30% taught the usage of an interspace brush or dental floss. Moreover, less than 10% of oral health professionals taught oral health care in lectures or practical oral health care. CONCLUSIONS: This study revealed problems associated with oral assessment and health care education in Japanese nursing schools. To address these, support from oral health care professionals is required. Further studies are also required to reveal problems in oral assessment and health care education in other nursing schools that do not offer a bachelor's degree programme in Japan and other countries.

Purification, crystallization and preliminary X-ray analysis of OsAREB8 from rice, a member of the AREB/ABF family of bZIP transcription factors, in complex with its cognate DNA.

The AREB/ABF family of bZIP transcription factors play a key role in drought stress response and tolerance during the vegetative stage in plants. To reveal the DNA-recognition mechanism of the AREB/ABF family of proteins, the bZIP domain of OsAREB8, an AREB/ABF-family protein from Oryza sativa, was expressed in Escherichia coli, purified and crystallized with its cognate DNA. Crystals of the OsAREB8-DNA complex were obtained by the sitting-drop vapour-diffusion method at 277 K with a reservoir solution consisting of 50 mM MES pH 6.4, 29% MPD, 2 mM spermidine, 20 mM magnesium acetate and 100 mM sodium chloride. A crystal diffracted X-rays to 3.65 Å resolution and belonged to space group C222, with unit-cell parameters a = 155.1, b = 206.7, c = 38.5 Å. The crystal contained one OsAREB8-DNA complex in the asymmetric unit.

Nurses' Perceptions of Oral Health Care Provision After the COVID-19 Lockdown.

OBJECTIVE: This study aimed to investigate nurses' perceptions of oral health care provision to inpatients in Japanese hospitals and the infection control measures taken by them after the coronavirus disease 2019 (COVID-19) lockdown to promote collaborative oral health care. METHOD: The participants were 1037 nurses working in inpatient wards at 4 hospitals in Fukuoka Prefecture, Japan. Data were collected through a questionnaire survey approximately 6 months after the first COVID-19 lockdown. RESULTS: More than 90% of the 734 nurses participating in this study positively perceived the preventive effect of oral health care on aspiration pneumonia, ventilator-associated pneumonia, and viral infection. However, approximately half of them had negative perceptions about their knowledge and confidence regarding the control of COVID-19 with oral health care provision, and 84.7% expected to be provided with the necessary information by oral health professionals. Further, 537 nurses (73.2%) provided oral health care to their patients; 9 nurses (1.7%) responded that those patients who received oral health care decreased after the lockdown; and 12 (2.4%) responded that they could no longer collaborate with oral health professionals because of the lockdown. Additionally, 41.7% of them used neither protective glasses nor face shields even after the lockdown began. CONCLUSIONS: This study showed that almost all the nurses perceived the benefcial effect of oral health care for the prevention of viral infection and pneumonia. However, some nurses perceived that their oral health care provision and collaborative oral health care were negatively affected. It also showed that most nurses' knowledge, confidence, and use of infection control measures were insufficient. The results indicate that oral health professionals should support nurses in providing oral health care by providing them with information on COVID-19 infection control measures to prevent infection transmission.

Structure of flap endonuclease 1 from the hyperthermophilic archaeon Desulfurococcus amylolyticus.

Flap endonuclease 1 (FEN1) is a key enzyme in DNA repair and DNA replication. It is a structure-specific nuclease that removes 5'-overhanging flaps and the RNA/DNA primer during maturation of the Okazaki fragment. Homologues of FEN1 exist in a wide range of bacteria, archaea and eukaryotes. In order to further understand the structural basis of the DNA recognition, binding and cleavage mechanism of FEN1, the structure of FEN1 from the hyperthermophilic archaeon Desulfurococcus amylolyticus (DaFEN1) was determined at 2.00 Šresolution. The overall fold of DaFEN1 was similar to those of other archaeal FEN1 proteins; however, the helical clamp and the flexible loop exhibited a putative substrate-binding pocket with a unique conformation.

Expression, purification, crystallization and preliminary X-ray analysis of the KaiC-like protein PH0187 from the hyperthermophilic archaeon Pyrococcus horikoshii OT3.

KaiC is the central protein in the circadian rhythm in cyanobacteria. The 28 kDa KaiC-like protein PH0187 from the hyperthermophilic archaeon Pyrococcus horikoshii was expressed in Escherichia coli, purified and crystallized using the sitting-drop vapour-diffusion method at 293 K. Crystals of PH0187 were obtained using a reservoir solution consisting of 1.0 M ammonium phosphate monobasic and 0.1 M sodium citrate tribasic pH 5.3 (the final pH value of the reservoir solution was 4.8) and diffracted X-rays to 2.75 Šresolution. The crystal of PH0187 belonged to space group P6(3)22, with unit-cell parameters a=b=239.1, c=106.5 Å. The crystal contained four PH0187 molecules in the asymmetric unit.

A cysteine endopeptidase ("dionain") is involved in the digestive fluid of Dionaea muscipula (Venus's fly-trap).

The carnivorous plant Dionaea muscipula (Venus's flytrap) secretes proteinases into the digestive fluid to digest prey proteins. In this study, we obtained evidence that the digestive fluid contains a cysteine endopeptidase, presumably belonging to the papain family, through inhibitor studies and partial amino acid sequencing of the major SDS-PAGE band protein. The name "dionain" is proposed for the enzyme.

A Case of Recalcitrant Phaeohyphomycosis of the Face Caused by Exophiala lecanii-corni.

We describe a case of recalcitrant phaeohyphomycosis caused by Exophiala lecanii-corni, which was previously reported as Exophiala jeanselmei, infection. A 63-year-old Japanese woman presented with a 15-year history of multiple pruritic erythematous patches and plaques on the face. Histopathological examination and fungal culture revealed phaeohyphomycosis by E. jeanselmei. The attempted treatments included 6 g/day 5-flucytosine (5-FC), 100 mg/day itraconazole (ITCZ), and local hyperthermia. 5-FC was effective initially, but the patient deteriorated after discontinuation. Subsequently, she was referred to our hospital. Histopathological examination showed granuloma with multinucleated giant cells with infiltrating fungal hyphae in the dermis. The causative fungus was finally identified as E. lecanii-corni by ribosomal RNA gene analysis. The patient improved after receiving 200 mg/day ITCZ orally for 15 months with local hyperthermia. In the present case, we confirmed the identification of E. lecanii-corni as the causative agent by molecular methods. We also emphasize the importance of combination therapy with antimycotic agents and local hyperthermia in phaeohyphomycosis.

Effect of multi-professional education on the perceptions and awareness of oral health care among undergraduate nursing students in a nursing school.

OBJECTIVE: This study investigates the effects of a study course in oral health care on the perceptions of nursing students. The course was designed and evaluated by a multi-professional team at a Japanese nursing school. METHOD: The subjects were 119 nursing students. They participated in the oral health course that comprised 45h of training in 4 years. These were designed and taught by oral health professionals, a certified speech-hearing therapist, and nurses. Questionnaires were distributed to subjects to compare their perceptions and awareness about oral health care before, in between, and after the courses. A chi-square test was used to compare the data. RESULTS: After completing the courses, more than 95% of the participants were interested in the oral health care practice and expected to collaborate with oral health professionals after getting qualified. Additionally, they understood the effectiveness of oral health care for the prevention of aspiration pneumonia and perceived that oral health care should be provided to hospitalized patients and community-dwelling older adults. Their awareness of the need to learn techniques for tooth brushing support, salivary gland massage, oral management, swallowing training, removing tongue coating, and gargling, both in theory and practice, was significantly improved. CONCLUSION: Multi-professional education has the potential to improve the awareness of nursing students of oral health care and promote collaborative oral health care in the future.

Crystallization and preliminary X-ray analysis of 5-keto-D-gluconate reductase from Gluconobacter suboxydans IFO12528 complexed with 5-keto-D-gluconate and NADPH.

NADPH-dependent 5-keto-D-gluconate reductase from Gluconobacter suboxydans IFO12528 (5KGR) catalyzes oxidoreduction between 5-keto-D-gluconate and D-gluconate with high specificity. 5KGR was expressed in Escherichia coli, purified and crystallized with 5-keto-D-gluconate and NADPH using the sitting-drop vapour-diffusion method at 288 K. A crystal of the 5KGR-NADPH complex was obtained using reservoir solution containing PEG 4000 as a precipitant and diffracted X-rays to 1.75 Šresolution. The crystal of the complex belonged to space group P4(2)2(1)2, with unit-cell parameters a=b=128.6, c=62.9 Å. A crystal of the 5KGR-NADPH-5-keto-D-gluconate complex was prepared by soaking the 5KGR-NADPH complex crystal in reservoir solution supplemented with 100 mM 5-keto-D-gluconate and 10 mM NADPH for 20 min and diffracted X-rays to 2.26 Šresolution. The crystal of the ternary complex belonged to space group P4(2)2(1)2, with unit-cell parameters a=b=128.7, c=62.5 Å. Both crystals contained two molecules in the asymmetric unit.