High throughput screening of pure silica zeolites for CF4 capture from electronics industry gas.

The capture and separation of CF4 from CF4/N2 mixture gas is a crucial issue in the electronics industry, as CF4 is a commonly used etching gas and the ratio of CF4 to N2 directly affects process efficiency. Utilizing high-throughput computational screening techniques and grand canonical Monte Carlo (GCMC) simulations, we comprehensively screened and assessed 247 types of pure silicon zeolite materials to determine their adsorption and separation performance for CF4/N2 mixtures. Based on screening, the relationships between the structural parameters and adsorption and separation properties were meticulously investigated. Four indicators including adsorption selectivity, working capacity, adsorbent performance score (APS), and regenerability (R%) were used to evaluate the performance of adsorbents. Based on the evaluation, we selected the top three best-performing zeolite structures for vacuum swing adsorption (LEV, AWW and ESV) and pressure swing adsorption (AVL, ZON, and ERI) processes respectively. Also, we studied the preferable adsorption sites of CF4 and N2 in the selected zeolite structures through centroid density distributions at the molecule level. We expect the study may provide some valuable guidance for subsequent experimental investigations on adsorption and separation of CF4/N2.

[Responses of radial growth of Quercus mongolica to stand density and climatic factors in a mountainous area of eastern Liaoning Province, China]. / è¾½ä¸œå±±åŒºè’™å¤æ Žå¾„å‘ç”Ÿé•¿å¯¹æž—åˆ†å¯†åº¦å’Œæ°”å€™å› å­çš„å“åº”.

To explore the effects of stand density and climatic factors on radial growth of Quercus mongolica, we used tree ring chronology to examine the radial growth changes in a secondary Q. mongolica forest under different levels of stand density (thinning). The meteorological data combined with the driving factors of Q. mongolica growth were analyzed. The results showed that the radial growth of Q. mongolica was significantly affected by stand density. The mean annual radial growth of Q. mongolica was 3.12 mm in low-density virgin forest, 1.55 and 1.42 mm in the two medium-density secondary forests, respectively, and 0.96 mm in high-density secondary forest. The thinning intensity of 20% had a limited effect on promoting the radial growth recovery of high-density forest (1900 trees·hm-2), but had a significant effect on medium-density forest (1600 trees·hm-2). The radial growth of Q. mongolica was sensitive to the precipitation changes in January and February of the current year. Thinning reduced the sensitivity of Q. mongolica radial growth to climate. Under scenarios of climate warming and drying, density regulation could be beneficial in mitigating the adverse effects of climate change on the growth of Q. mongolica.

Dynamic structural insights into the molecular mechanism of DNA unwinding by the bacteriophage T7 helicase.

The hexametric T7 helicase (gp4) adopts a spiral lock-washer form and encircles a coil-like DNA (tracking) strand with two nucleotides bound to each subunit. However, the chemo-mechanical coupling mechanism in unwinding has yet to be elucidated. Here, we utilized nanotensioner-enhanced Förster resonance energy transfer with one nucleotide precision to investigate gp4-induced unwinding of DNA that contains an abasic lesion. We observed that the DNA unwinding activity of gp4 is hindered but not completely blocked by abasic lesions. Gp4 moves back and forth repeatedly when it encounters an abasic lesion, whereas it steps back only occasionally when it unwinds normal DNA. We further observed that gp4 translocates on the tracking strand in step sizes of one to four nucleotides. We propose that a hypothetical intermediate conformation of the gp4-DNA complex during DNA unwinding can help explain how gp4 molecules pass lesions, providing insights into the unwinding dynamics of gp4.

[Spatial structure characteristics of the main tree species in a mixed broadleaved Korean pine (Pinus koraiensis)forest in a mountainous area of eastern Liaoning Province, China]. / è¾½ä¸œå±±åŒºåŽŸå§‹é˜”å¶çº¢æ¾æž—ä¸»è¦æ ‘ç§ç©ºé—´ç»“æž„ç‰¹å¾.

Maintaining forest structural diversity is generally considered as an effective way to preserve forest stability and biodiversity. The spatial structure characteristics of the dominant tree species in a climax community were investigated in a primary mixed broadleaved Korean pine (Pinus koraiensis) forest in a mountainous area of eastern Liaoning. Stand spatial structure parameters were determined based on the relationships among neighboring trees. The climax communities were used as a theoretical reference for optimizing the spatial structure of a low-quality secondary forest and monoculture plantation. The diameter distribution of the trees in the pine forest exhibited an inverse J-shape, indicating that understory regeneration was relatively good and with certain proportion of large-diameter trees. The main tree species were randomly distributed across the whole plot (=0.507) and in an intensively mixed state (=0.82). An average DBH comparison of trees in the stand indicated that they were at a intermediate status (=0.506). There was a differentiation among different dominances along the high intensity mixed dimension in the stand, indicating an optimal distribution of understory trees and the rational utilization of resources. Trees in the small diameter category were at a state of complete compression, while canopy trees were at a state of complete dominance in terms of their vertical space. Individuals of each dominant tree species were randomly scattered, with a random pattern of individuals throughout the climax community.

Long Noncoding RNA CRNDE Promotes Proliferation of Gastric Cancer Cells by Targeting miR-145.

BACKGROUND/AIMS: The colorectal neoplasia differentially expressed (CRNDE) gene is a long noncoding RNA (lncRNAs) that is upregulated in colorectal cancer and glioma. Here, we investigated the regulatory function of CRNDE in gastric cancer (GC). METHODS: CRNDE and miR-145 expression were assayed by qRT-PCR, and E2F3 protein expression was measured by western blotting. A luciferase reporter assay was used to detect the direct regulation of miR-145 by CRNDE. Cell viability and colony formation of human GC cells were detected using MTT and colony formation assay, respectively. RESULTS: CRNDE was highly expressed in GC cell lines and tissues; overexpression of CRNDE increased GC cell viability and promoted colony formation. Knockdown of CRNDE did not result in loss of expression-related effects on cell proliferation and colony formation. Further investigation revealed that the miR-145 target gene E2F3 was strongly expressed following CRNDE competitive molecular sponging of miR-145. CONCLUSION: CRNDE acted as a growth-promoting lncRNA in GC and maybe a potential target of GC treatment.

A pig model of ischemic mitral regurgitation induced by mitral chordae tendinae rupture and implantation of an ameroid constrictor.

A miniature pig model of ischemic mitral regurgitation (IMR) was developed by posterior mitral chordae tendinae rupture and implantation of an ameroid constrictor. A 2.5-mm ameroid constrictor was placed around the left circumflex coronary artery (LCX) of male Tibetan miniature pigs to induce ischemia, while the posterior mitral chordae tendinae was also ruptured. X-ray coronary angiography, ECG analysis, echocardiography, and magnetic resonance imaging (MRI) were used to evaluate heart structure and function in pigs at baseline and one, two, four and eight weeks after the operation. Blood velocity of the mitral regurgitation was found to be between medium and high levels. Angiographic analyses revealed that the LCX closure was 10-20% at one week, 30-40% at two weeks and 90-100% at four weeks subsequent ameroid constrictor implantation. ECG analysis highlighted an increase in the diameter of the left atria (LA) at two weeks post-operation as well as ischemic changes in the left ventricle (LV) and LA wall at four weeks post-operation. Echocardiography and MRI further detected a gradual increase in LA and LV volumes from two weeks post-operation. LV end diastolic and systolic volumes as well as LA end diastolic and systolic volume were also significantly higher in pig hearts post-operation when compared to baseline. Pathological changes were observed in the heart, which included scar tissue in the ischemic central area of the LV. Transmission electron microscopy highlighted the presence of contraction bands and edema surrounding the ischemia area, including inflammatory cell infiltration within the ischemic area. We have developed a pig model of IMR using the posterior mitral chordae tendineae rupture technique and implantation of an ameroid constrictor. The pathological features of this pig IMR model were found to mimic the natural history and progression of IMR in patients.

JMJD2A predicts prognosis and regulates cell growth in human gastric cancer.

A number of JmjC domain-containing histone demethylases have been identified and biochemically characterized in mammalian. JMJD2A is a transcriptional cofactor and enzyme that catalyzes demethylation of histone H3 lysines 9 and 36. Here in this study, we aim to explore the role of JMJD2A in human gastric cancer. Quantitative real-time PCR, Western blot and immunohistochemistry analyses reveal higher expression of JMJD2A in clinical gastric cancer tissues than that in normal gastric mucosa. JMJD2A expression is associated with tumor stage and nodal status, and high level of JMJD2A predicts poor overall and disease-free survival. Univariate and multivariate survival analyses demonstrate that JMJD2A could serve as an independent prognostic factor. Furthermore, we show that inhibition the expression of JMJD2A attenuates the growth and transformation of three lines of gastric cancer cells. Mechanically, JMJD2A knockdown induces apoptosis of gastric cancer cells by up-regulating the expression of pro-apoptotic proteins and by down-regulating anti-apoptotic protein. Finally, we show that JMJD2A level is correlated with the level of the pro-apoptotic microRNA miR-34a in gastric cancer tissues and JMJD2A represses the expression of miR-34a by decreasing its promoter activity. Those findings demonstrate that JMJD2A regulates gastric cancer growth and serves as an independent prognostic factor, and implicate that JMJD2A may be a promising target for intervention.

The RNA-binding protein PCBP2 facilitates gastric carcinoma growth by targeting miR-34a.

Gastric carcinoma is the fourth most common cancer worldwide, with a high rate of death and low 5-year survival rate. However, the mechanism underling gastric cancer is still not fully understood. Here in the present study, we identify the RNA-binding protein PCBP2 as an oncogenic protein in human gastric carcinoma. Our results show that PCBP2 is up-regulated in human gastric cancer tissues compared to adjacent normal tissues, and that high level of PCBP2 predicts poor overall and disease-free survival. Knockdown of PCBP2 in gastric cancer cells inhibits cell proliferation and colony formation in vitro, whereas opposing results are obtained when PCBP2 is overexpressed. Our in vivo subcutaneous xenograft results also show that PCBP2 can critically regulate gastric cancer cell growth. In addition, we find that PCBP2-depletion induces apoptosis in gastric cancer cells via up-regulating expression of pro-apoptotic proteins and down-regulating anti-apoptotic proteins. Mechanically, we identify that miR-34a as a target of PCBP2, and that miR-34a is critically essential for the function of PCBP2. In summary, PCBP2 promotes gastric carcinoma development by regulating the level of miR-34a.

[Clinical analysis of CT guided unilateral PVP for the treatment of osteoporotic vertebral compression fracture in senile patients].

OBJECTIVE: To evaluate the therapeutic effect and security of CT guided unilateral percutaneous vertebroplasty (PVP) for the treatment of osteoporotic vertebral compression fracture (OVCF) in senile patients. METHODS: From April 2009 to June 2010, 26 patients undergoing CT guided unilateral percutaneous vertebroplasty were analyzed retrospectively. There were 9 males and 17 females,ranging in age from 60 to 85 years with an average of (67.50+/-6.76) years, ranging in course of disease from 2 to 30 days with an average of (8.92+/-4.36) d. The affected segments involved 35 vertebras. The major clinical manifestations of OVCF were lumbar-back pain (especially when turning over or stooping down) and unable to bear. The needle was punctured into vertebral of lesions through unilateral puncture under the CT guidance; and then 3-5 ml bone cement was injected into vertebral. Antibiotic was used 3 days to prevent postoperative infections. Postoperative complications were observed after operation, such as local leakage of bone cement, penetrating spinal cord and/or segmental spinal nerve injuries and pulmonary embolism. X-ray was used to measure the height of anterior, middle and exterior of vertebral before and after treatment. A visual analog scale (VAS) scoring was applied to evaluate pain score preoperative, 48 hours postoperative and the terminal follow-up. RESULTS: Twenty-six patients achieved success in punctuation without serious complications. Local leakage of bone cement occurred in 6 cases, but without clinical symptoms or signs. One patient suffered from acute intraoperative reactions to bone cement and relieved by 5 mg dexamethasone and oxygen. All patients were followed up for 6 to 12 months [averaged (8.4+/-1.6) months]. The postoperative vertebrae height was higher than preoperative,but there was no statistical difference between postoperative and preoperative (P>0.05). Preoperative VAS scores was 7.63+/-0.92, postoperative score was 3.00+/-1.09, the final follow-up score was 2.38+/-1.17; there was significant difference between preoperative and postoperative at 48 hours (P<0.05), but there was no statistical difference between final follow-up and postoperative at 48 hours (P>0.05). CONCLUSION: Unilateral PVP under CT guided can increase the vertebral strength and stabilize vertebral body,and the procedure is a safe and effective method for OVCF in elderly patients.

[Advances on olfactory receptor gene].

The olfactory sense plays a key role in animals'life time. The main gene related with olfaction was olfactory receptor (OR) gene. This review introduced the structure, expression regulation, distribution, molecular evolution and polymorphism of OR gene. The relationship between OR gene and olfactory function and olfactory deficits was also discussed.

[Relationships between coefficient of variation of diameter and height and competition index of main coniferous trees in Changbai Mountains].

A total of 1139 trees from 8 clear-cut stands dominated by fir, spruce, and pine in the Changbai Mountains were selected to study the relationships between the coefficient of variation of diameter and height and the competition index of the three main coniferous tree species in the Mountains. For the test tree species, the variation of height vs. diameter class was relatively small, while the variations of diameter and height vs. age class were larger, with the largest coefficient of variation of diameter vs. age class. The traditional height-diameter models could better reflect the real growth of trees, whereas the diameter-age or height-age models were not good enough. Competition was the main factor inducing the variations of tree diameter and height, suggesting that incorporating the competition index to the traditional models of tree growth and height could improve the model accuracy significantly.

Rv0901 from Mycobacterium tuberculosis, a possible novel virulent gene proved through the recombinant Mycobacterium smegmatis.

The function of protein-coding gene Rv0901 of Mycobacterium tuberculosis, which belongs to the cell wall and cell processes category, is not yet clear. To explore its features, we amplified this gene from the H37Rv genome, and His-tagged Rv0901 protein was expressed and purified. Also, a recombinant plasmid bearing Rv0901 was constructed and electroporated into a virulent Mycobacterium smegmatis, using shuttle expression vector pMV261. Transformants were induced to express a predicted protein of Rv0901, identified by SDS-PAGE. Rv0901 protein and recombinant M. smegmatis were used to expose mammalian cells. In addition we studied the effect of protein or recombinant M. smegmatis on cells and in animals with regard to survival ratio, apoptosis ratio, quantum of nitric oxide, and gamma interferon. Together, gene function, protein function, and animal test results suggest that Rv0901 has some relationship with the virulence and immunogenicity of M. tuberculosis.

[Recombinant plasmid constructed and cytotoxicity studied for outer membrane protein LipL32 gene of Leptospira strain 017].

OBJECTIVE: To construct the recombinant plasmid containing the outer membrane protein LipL32 gene of Leptospira strain 017 and to study on the cytotoxicity of the expression protein. METHODS: By the polymerase chain reaction (PCR), the LipL32 gene was amplified from Leptospira strain 017 genome and cloned into pET32a(+) with enzyme digestion, then used to transform E. coli JM109. After induced with IPTG, the target protein was expressed and used to immunize New zealand white rabbit. Western Blotting identified the immunogenicity of the expressed protein. Then the purified and renatured protein was acted on ECV304 cell so as to get its cytotoxicity detected by examining the LDH and NO (nitrogen monoxide) release from cell. RESULTS: The full length of the LipL32 gene about 816 bp was obtained by PCR. The recombinant plasmid was identified by enzyme digestion, PCR and DNA sequencing. After induced with IPTG, the expressed protein existed mainly in the form of inclusion bodies about 52 x 10(3) (relative molecular mass) which was consistent with the expected size of the fused protein. After rabbit immunity, the titre of the produced multiclonal antibody reached 1 : 32 000 measured by ELISA. Western Blotting analysis found a positive band specifically in the target protein position. The release of the LDH and NO of the ECV304 cell treated with LipL32 had significant increase compared with the control group. CONCLUSION: The recombinant plasmid containing LipL32 gene is successfully constructed and can express the target protein in E. coli JM109. The expressed target protein has cytotoxicity.

[Expression and identification of gene Loa22 from the virulent strain of serovar Lai of L. interrogans and its cytotoxicity to macrophages].

OBJECTIVE: To study the function of Loa22 gene from virulent serovar Lai. L. interrogans by expressing its protein. METHODS: The recombinant plasmid with Loa22 was constructed and its expression was induced by IPTG. The expression product was identified by SDS-PAGE and Western Blotting and purified with GST-affinity chromatography. The purified protein was applied to mice macrophages ANA-1 cells purified by GST-affinity column and exerted to ANA-1 cells. The cytotoxicity of purified protein to ANA-1 was evaluated by detecting LDH activity in culture medium, XTT aborbtion and apoptosis ration. RESULTS: The recombinant plasmid with Loa22 mature peptide was constructed successfully and the protein was purified subsequently. Significant higher level of LDH activity and apoptosis ratio and lower XTT absorption were observed by comparison of expression protein treated cells and those untreated. CONCLUSION: Loa22 had a toxic effect on ANA-1 and the gene Loa22 might be a virulent-related gene of L. interrogans.

[Construction of the eukaryotic recombinant vector and expression of the outer membrane protein LipL32 gene from Leptospira serovar Lai].

AIM: To construct the eukaryotic experssion vector of LipL32 gene from Leptospira serovar Lai and express the recombinant plasmid in COS-7 cell. METHODS: The LipL32 gene was amplified from Leptospira strain 017 genomic DNA by PCR and cloned into pcDNA3.1, through restriction nuclease enzyme digestion. Then the recombinant plasmid was transformed into E.coli DH5alpha. After identified by nuclease digestion, PCR and sequencing analysis, the recombinant vector was transfected into COS-7 cell with lipsome. The expression of the target gene was detected by RT-PCR and Western blot. RESULTS: The eukaryotic experssion vector pcDNA3.1-LipL32 was successfully constructed and stably expressed in COS-7 cell. CONCLUSION: The eukaryotic recombinant vector of outer membrane protein LipL32 gene from Leptospira serovar Lai can be expressed in mammalian cell, which provides an experimental basis for the application of the Leptospira DNA vaccine.

[Immunogenicity of DNA vaccine prime-BCG boost against Mycobacterium tuberculosis].

AIM: To compare the immunogenicity of vaccine strategies about combined DNA prime-BCG boost and DNA or BCG vaccination only. METHODS: BALB/c mice were divided into four groups each containing 6 mice, and all mice received three immunizations at 2 weeks interval. One group of mice was vaccinated with PBS (PBS group); one group was vaccinated twice at 0 week and 2 weeks with combined DNA expressing two mycobacterial antigens, ESAT-6 and antigen 85A respectively; and then boosted with BCG at 4 weeks (DNA/BCG group); another group was vaccinated twice with combined DNA at 0 week, 2 weeks and 4 weeks(DNA/DNA group); and the final group received PBS twice at 0 week and 2 weeks and then vaccinated with BCG at 4 weeks(BCG group). Specific IgG antibody in serum of mice was determined with indirect ELISA in 4 weeks, 6 weeks, 8 weeks respectively after final vaccination.The splenic lymphocytes of mice were separated and stimulated with PPD to measure their proliferation by XTT, and to evaluate the production of interferon-r(IFN-gamma) and IL-4 in cell suspensions of spleen cells by ELISA. RESULTS: PPD could stimulate specific IgG responses in DNA/BCG, DNA/DNA and BCG groups (DNA/DNA group>DNA/BCG group and BCG group), and the most significant response occurred in 12 weeks; the splenic lymphocyte proliferation reactions and IFN-gamma and IL-4 production was detectable in DNA/BCG, DNA/DNA and BCG groups and DNA/BCG group induced significant higher production, especially in 12 weeks. CONCLUSION: Priming with the combined DNA vaccines and boost with attenuated M. bovis vaccine (BCG) could enhance specific cell reactions and high level IFN-gamma compared with DNA or attenuated M. bovis vaccine alone.

[Construction and screen of recombinant BCG strain expressing and secreting human interleukin 12 protein].

OBJECTIVE: To screen and construct the recombinant Bacillus Calmette-Guerin (rBCG) strain expressing and secreting the human interleukin 12 (rBCG-12). METHODS: IL-12 complete gene including p40 and p35 subunits was amplified by PCR from a plasmid pORF-h IL-12 and cloned into E. coli-Mycobacteria shuttle vector pMV361. The recombinant vector was named as rpMV-IL-12. rpMV-IL-12 was confirmed by DNA sequencing, and then rpMV-IL-12 was used, by electroporation way, to transform the BCG for getting the recombinant rBCG-12 strain. The positive rBCG-12 clone was screened and identified by kanamycin resistance and IL-12 target gene PCR amplification. The IL-12 protein expression of rBCG-12 was induced with heat shock reaction. Then rBCG-12 culture supernatant and bacterial precipitation were collected respectively and analyzed with SDS-PAGE electrophoresis for their protein components. RESULTS: The recombinant shuttle plasmid rpMV-IL-12 was constructed successfully. The sequence of amplified IL-12 gene was consistent with GenBank report. By SDS-PAGE electrophoresis, it was confirmed that the IL-12 protein could express and secrete into the supernatant of rBCG-12 strain culture. CONCLUSION: The recombinant BCG strain expressing human IL-12 protein, rBCG-12 strain, is constructed and screened successfully. It is the foundation for further research on rBCG-12 immune function.

[Protein-protein interaction between hypothetical protein Rv1246c and Rv1247c of Mycobacterium tuberculosis].

OBJECTIVE: To investigate the protein-protein interaction between hypothetical protein Rv1246c and Rv1247c of Mycobacterium tuberculosis. METHODS: By PCR technique, the complete open-reading frame sequences of Rv1246c and Rv1247c gene were amplified from the M. tuberculosis H37Rv genomic DNA as template. The PCR-amplified cDNAs of Rv1247c and Rv1246c gene were subcloned into pGBKT7 and pGADT7-Rec vector respectively for constructing recombinant plasmids pGBKT7-Rv1247c and pGADT7-Rv1246c. After verified by restriction endonuclease digestion and DNA sequence determination, the recombinant vectors were used to transform the yeast cell AH109 by lithium acetate method. RESULTS: The yeast cells co-transformed with pGBKT7-Rv1247c and pGADT7-Rv1246c grew on SD/-Ade/-His/-Leu/-Trp plates, and the beta-galactosidase activity assays showed the positive signal. CONCLUSION: The hypothetical protein Rv1246c and Rv1247c could interact with each other in yeast cells.

[Construction of recombinant E. coli-L. interrogans shuttle plasmid pGKINVA and screening recombinant leptospira strains].

OBJECTIVE: To further investigate pathogenic function of invA in Leptospira, recombinant L. biflexa-Escherichia coli shuttle vector pGKINVA was constructed, and electropored into L. biflexa strain Patoc I . METHODS: The invA gene was cloned into shuttle vector pGKble24 to construct a recombinant L. biflexa-Escherichia coli shuttle vector pGKINVA. The recombinant vectors were electropored into L. biflexa serovar Patoc strain Patoc I . RESULTS: A 558 bp invA was amplified from L. interrogans serovars Lai strain 017 and ligated with Aat II and Xma I digested pGKble24. After screening by kanamycin and blue/white color, the recombinant pGKINVA was obtained and sequenced. Subsequently, the recombinant pGKINVA was electropored into L. biflexa strain Patoc I. The selected mutants were identified by PCR. CONCLUSION: Recombinant L. biflexa-Escherichia coli shuttle vector with invA insert was constructed and two strains of pGKINVA transformed Leptospira were obtained. These pGKINVA transformed Leptospira strains would provid an experimental model to investigate potential pathogenic functions of invA in vivo.

[Molecular cloning and expression of hypothetical proteins Rv1494 and Rv1495 of M.tuberculosis H37Rv strain].

OBJECTIVE: The mechanism by which M.tuberculosis persists and survives in host macrophage is not fully understood, however, the M. tuberculosis chromosome-encoded TA loci perform functions possibly of signaling to these processes. To explore the biological functions of M. tuberculosis chromosome-encoded TA loci, the Rv1494 and Rv1495 genes of M.tuberculosis H37Rv strain were cloned and expressed. METHODS: The hypothetical proteins Rv1494 and Rv1495 were bioinformatically analyzed by means of Bioedit software, Dnaman software and Pfam database. The complete open-reading frame sequences of Rv1494 and Rv1495 genes were amplified by PCR using M.tuberculosis H37Rv genomic DNA as the template, and the PCR products were cloned into prokaryotic expression vector pET32a(+), respectively. After induction of expressions in E.coli host strain BL21 (DE3), the recombinant proteins were purified and detected by Western blotting. RESULTS: According to bioinformatic analysis, the hypothetical proteins of Rv1494 and Rv1495 genes shared some homologies with mazEF family, one of E. coli chromosomal TA loci (homology at 26% and 29.5%). Sequence analysis showed that the inserted target genes and its reading frames were completely correct. The recombinant plasmids were induced with IPTG to effectively express the fusion proteins with relative molecular mass coincident with prediction. The specific positive signals were identified from the immunoblots. CONCLUSION: For the first time, the Rv1494 and Rv1495 genes of M.tuberculosis H37Rv strain were cloned and its prokaryotic expression vectors were constructed successfully in this experiment, which may facilitate further functional study of this mazEF-like gene pair.