Emission control status and future perspectives of diesel trucks in China.

Chinese diesel trucks are the main contributors to NOx and particulate matter (PM) vehicle emissions. An increase in diesel trucks could aggravate air pollution and damage human health. The Chinese government has recently implemented a series of emission control technologies and measures for air quality improvement. This paper summarizes recent control technologies and measures for diesel truck emissions in China and introduces the comprehensive application of control technologies and measures in Beijing-Tianjin-Hebei and surrounding regions. Remote online monitoring technology has been adopted according to the China VI standard for heavy-duty diesel trucks, and control measures such as transportation structure adjustment and heavy pollution enterprise classification control continue to support the battle action plan for pollution control. Perspectives and suggestions are provided for promoting pollution control and supervision of diesel truck emissions: adhere to the concept of overall management and control, vigorously promote the application of systematic and technological means in emission monitoring, continuously facilitate cargo transportation structure adjustment and promote new energy freight vehicles. This paper aims to accelerate the implementation of control technologies and measures throughout China. China is endeavouring to control diesel truck exhaust pollution. China is willing to cooperate with the world to protect the global ecological environment.

Click-chemistry-based protocol for detecting 4-octyl-itaconate-alkylated proteins in primary mouse macrophages.

4-Octyl itaconate (4-OI), a derivative of itaconate, inhibits inflammation by alkylating its target proteins. Here, we present a click-chemistry-based protocol for detecting 4-OI-alkylated proteins in mouse primary bone-marrow-derived macrophages (BMDMs) by using an itaconate-alkyne (ITalk) probe. We describe steps for culturing and treating BMDMs and details on using click chemistry in the cell lysate. We also detail procedures for detecting alkylated proteins by western blot. For complete details on the use and execution of this protocol, please refer to Su et al.1.

The next Nobel Prize in chemistry or in physiology or medicine.

In early October, the Nobel Prizes will honor groundbreaking discoveries. After the anticipated recognition of Katalin Karikó and Drew Weissman in 2023 for the development of RNA modifications that enabled the SARS-CoV-2 mRNA vaccine, we eagerly consider the next topics to be awarded. In the September 30th anniversary special issue of Cell Chemical Biology, we ask researchers from a range of backgrounds, what topic do you think deserves the next Nobel Prize in chemistry or in physiology or medicine, and why?

Immunothrombosis: A bibliometric analysis from 2003 to 2023.

BACKGROUND: Immunothrombosis is a physiological process that constitutes an intravascular innate immune response. Abnormal immunothrombosis can lead to thrombotic disorders. With the outbreak of COVID-19, there is increasing attention to the mechanisms of immunothrombosis and its critical role in thrombotic events, and a growing number of relevant research papers are emerging. This article employs bibliometrics to discuss the current status, hotspots, and trends in research of this field. METHODS: Research papers relevant to immunothrombosis published from January 1, 2003, to May 29, 2023, were collected from the Web of Science Core Collection database. VOSviewer and the R package "Bibliometrix" were employed to analyze publication metrics, including the number of publications, authors, countries, institutions, journals, and keywords. The analysis generated visual results, and trends in research topics and hotspots were examined. RESULTS: A total of 495 target papers were identified, originating from 58 countries and involving 3287 authors from 1011 research institutions. Eighty high-frequency keywords were classified into 5 clusters. The current key research topics in the field of immunothrombosis include platelets, inflammation, neutrophil extracellular traps, Von Willebrand factor, and the complement system. Research hotspots focus on the mechanisms and manifestations of immunothrombosis in COVID-19, as well as the discovery of novel treatment strategies targeting immunothrombosis in cardiovascular and cerebrovascular diseases. CONCLUSION: Bibliometric analysis summarizes the main achievements and development trends in research on immunothrombosis, offering readers a comprehensive understanding of the field and guiding future research directions.

Structural basis for the type I-F Cas8-HNH system.

The Cas3 nuclease is utilized by canonical type I CRISPR-Cas systems for processive target DNA degradation, while a newly identified type I-F CRISPR variant employs an HNH nuclease domain from the natural fusion Cas8-HNH protein for precise target cleavage both in vitro and in human cells. Here, we report multiple cryo-electron microscopy structures of the type I-F Cas8-HNH system at different functional states. The Cas8-HNH Cascade complex adopts an overall G-shaped architecture, with the HNH domain occupying the C-terminal helical bundle domain (HB) of the Cas8 protein in canonical type I systems. The Linker region connecting Cas8-NTD and HNH domains adopts a rigid conformation and interacts with the Cas7.6 subunit, enabling the HNH domain to be in a functional position. The full R-loop formation displaces the HNH domain away from the Cas6 subunit, thus activating the target DNA cleavage. Importantly, our results demonstrate that precise target cleavage is dictated by a C-terminal helix of the HNH domain. Together, our work not only delineates the structural basis for target recognition and activation of the type I-F Cas8-HNH system, but also guides further developments leveraging this system for precise DNA editing.

Inhibition of human UDP-glucuronosyltransferase (UGT) enzymes by darolutamide: Prediction of in vivo drug-drug interactions.

Darolutamide is a potent second-generation, selective nonsteroidal androgen receptor inhibitor (ARI), which has been approved by the US Food and Drug Administration (FDA) in treating castrate-resistant, non-metastatic prostate cancer (nmCRPC). Whether darolutamide affects the activity of UDP-glucuronosyltransferases (UGTs) is unknown. The purpose of the present study is to evaluate the inhibitory effect of darolutamide on recombinant human UGTs and pooled human liver microsomes (HLMs), and explore the potential for drug-drug interactions (DDIs) mediated by darolutamide through UGTs inhibition. The product formation rate of UGTs substrates with or without darolutamide was determined by HPLC or UPLC-MS/MS to estimate the inhibitory effect and inhibition modes of darolutamide on UGTs were evaluated by using the inhibition kinetics experiments. The results showed that 100 µM darolutamide exhibited inhibitory effects on most of the 12 UGTs tested. Inhibition kinetic studies of the enzyme revealed that darolutamide noncompetitively inhibited UGT1A1 and competitively inhibited UGT1A7 and 2B15, with the Ki of 14.75 ± 0.78 µM, 14.05 ± 0.42 µM, and 6.60 ± 0.08 µM, respectively. In particular, it also potently inhibited SN-38, the active metabolite of irinotecan, glucuronidation in HLMs with an IC50 value of 3.84 ± 0.46 µM. In addition, the in vitro-in vivo extrapolation (IVIVE) method was used to quantitatively predict the risk of darolutamide-mediated DDI via inhibiting UGTs. The prediction results showed that darolutamide may increase the risk of DDIs when administered in combination with substrates of UGT1A1, UGT1A7, or UGT2B15. Therefore, the combined administration of darolutamide and drugs metabolized by the above UGTs should be used with caution to avoid the occurrence of potential DDIs.

Structural basis for the concerted antiphage activity in the SIR2-HerA system.

Recently, a novel two-gene bacterial defense system against phages, encoding a SIR2 NADase and a HerA ATPase/helicase, has been identified. However, the molecular mechanism of the bacterial SIR2-HerA immune system remains unclear. Here, we determine the cryo-EM structures of SIR2, HerA and their complex from Paenibacillus sp. 453MF in different functional states. The SIR2 proteins oligomerize into a dodecameric ring-shaped structure consisting of two layers of interlocked hexamers, in which each subunit exhibits an auto-inhibited conformation. Distinct from the canonical AAA+ proteins, HerA hexamer alone in this antiphage system adopts a split spiral arrangement, which is stabilized by a unique C-terminal extension. SIR2 and HerA proteins assemble into a ∼1.1 MDa torch-shaped complex to fight against phage infection. Importantly, disruption of the interactions between SIR2 and HerA largely abolishes the antiphage activity. Interestingly, binding alters the oligomer state of SIR2, switching from a dodecamer to a tetradecamer state. The formation of the SIR2-HerA binary complex activates NADase and nuclease activities in SIR2 and ATPase and helicase activities in HerA. Together, our study not only provides a structural basis for the functional communications between SIR2 and HerA proteins, but also unravels a novel concerted antiviral mechanism through NAD+ degradation, ATP hydrolysis, and DNA cleavage.

In situ fabrication of a plasmonic Bi@Bi2O2CO3 core-shell heterostructure for photocatalytic CO2 reduction: structural insights into selectivity modulation.

The precise design of active sites and light absorbers is essential for developing highly efficient photocatalysts for CO2 reduction. Core-shell heterostructures constructed based on large-sized plasmonic Bi metals are ideal candidates because of the utilization of full-spectrum light and effective charge separation. However, the mechanism of selectivity modulation of large-sized Bi@semiconductor photocatalysts has yet to be explored in depth. Herein, a plasmonic Bi@Bi2O2CO3 core-shell heterostructure was successfully synthesized via a facile solvothermal treatment in deep eutectic solvents, demonstrating highly efficient photocatalytic CO2 reduction. This structure features a sizeable Bi sphere with a thin, epitaxially grown Bi2O2CO3 shell, which allows for the utilization of the entire light spectrum. Additionally, the oxygen vacancies in the Bi2O2CO3 shell can rapidly trap electrons transferred from the Bi core via Bi-O-Bi bonds, thereby forming abundant electron-rich interfaces that serve as the active sites for activating reactant molecules and facilitating the reaction.

Concentration-Dependent Layer-Stacking and the Influence on Phase-Conversion in Colloidally Synthesized WSe2 Nanocrystals.

We report a synthesis of WSe2 nanocrystals in which the number of layers is controlled by varying the precursor concentration. By altering the ratios and concentrations of W(CO)6 and Ph2Se2 in trioctylphosphine oxide, we show that high [Se] and large Se/W ratios lead to an increased number of layers per nanocrystal. As the number of layers per nanocrystal is increased, the nanocrystal ensembles show less phase-conversion from the metastable 2M phase to the thermodynamically favored 2H phase. Density functional theory calculations indicate that the interlayer binding energy increases with the number of layers, indicating that the stronger interlayer interactions in multilayered nanocrystals may increase the energy barrier to phase-conversion. The results presented herein provide insights for directing phase-conversion in solution-phase syntheses of transition metal dichalcogenides.

Suitable fermentation temperature of forage sorghum silage increases greenhouse gas production: Exploring the relationship between temperature, microbial community, and gas production.

Silage is an excellent method of feed preservation; however, carbon dioxide, methane and nitrous oxide produced during fermentation are significant sources of agricultural greenhouse gases. Therefore, determining a specific production method is crucial for reducing global warming. The effects of four temperatures (10 °C, 20 °C, 30 °C, and 40 °C) on silage quality, greenhouse gas yield and microbial community composition of forage sorghum were investigated. At 20 °C and 30 °C, the silage has a lower pH value and a higher lactic acid content, resulting in higher silage quality and higher total gas production. In the first five days of ensiling, there was a significant increase in the production of carbon dioxide, methane, and nitrous oxide. After that, the output remained relatively stable, and their production at 20 °C and 30 °C was significantly higher than that at 10 °C and 40 °C. Firmicutes and Proteobacteria were the predominant silage microorganisms at the phylum level. Under the treatment of 20 °C, 30 °C, and 40 °C, Lactobacillus had already dominated on the second day of silage. However, low temperatures under 10 °C slowed down the microbial community succession, allowing, bad microorganisms such as Chryseobacterium, Pantoea and Pseudomonas dominate the fermentation, in the early stage of ensiling, which also resulted in the highest bacterial network complexity. According to random forest and structural equation model analysis, the production of carbon dioxide, methane and nitrous oxide is mainly affected by microorganisms such as Lactobacillus, Klebsiella and Enterobacter, and temperature influences the activity of these microorganisms to mediate gas production in silage. This study helps reveal the relationship between temperature, microbial community and greenhouse gas production during silage fermentation, providing a reference for clean silage fermentation.

Failure of the three-way catalyst (TWC) introduces "super emitters".

Vehicle exhaust is one of the major organic sources in urban areas. Old taxis equipped with failed three-way catalysts (TWCs) have been regarded as "super emitters". Compressed natural gas (CNG) is a regular substitution fuel for gasoline in taxis. The relative effect of fuel substitution and TWC failure has not been thoroughly investigated. In this work, vehicle exhausts from gasoline and CNG taxis with optimally functioning and malfunctioning TWCs are sampled by Tenax TA tubes and then analyzed by a comprehensive two-dimensional gas chromatography-mass spectrometer (GC×GC-MS). A total of 216 organics are quantified, including 80 volatile organic compounds (VOCs) and 132 intermediate volatility organic compounds (IVOCs). Failure of TWC introduces super emitters with 30 - 70 times emission factors (EFs), 60 - 112 times ozone formation potentials (OFPs), and 34 - 92 times secondary organic aerosols (SOAs) more than normal vehicles. Specifically, for the taxi with failed TWC, the total organic EF of CNG is 16 times that of gasoline, indicating that the failure of TWC exceeds the emission reduction achieved by CNG-gasoline substitution. A significant but unbalanced reduction of ozone and SOA is observed after TWC, whereas a notable "enrichment" in IVOCs was observed. Naphthalene is a typical IVOC component strongly associated with CNG-gasoline substitution and TWC failure, which is lacking in current VOC measurement. We especially emphasize that there is an urgent need to scrap vehicles with failed TWCs in order to significantly reduce air pollution.

Revisiting the estimation indicator for HONO emissions from light-duty vehicles.

Gaseous nitrous acid (HONO), playing a crucial role in the generation of hydroxyl (OH) radicals and thus secondary pollution, lacks a source. Vehicular emission is a significant HONO source and is usually estimated by a traditional estimation indicator (RHONO/NOx = 0.8 %). Nevertheless, with more direct measurements for vehicular HONO emissions, RHONO/NOx values have been reported to vary over a wide range. In this study, we conducted the driving tests with a chassis dynamometer for ten light-duty gasoline vehicles. HONO emission factors have realized a significant reduction with the updating of emission standards, with emission factors of 0.40 mg/km, 0.13 mg/km, and 0.06 mg/km for China IV, China V, and China VI vehicles, respectively. Besides precursors, water content and exhaust temperature were found to be possible decisive factors for initiating HONO generation. Furthermore, by coupling NOx emissions and combustion efficiency, we modified the estimation indicator for vehicular HONO emissions and a better estimation effect has been verified. Additionally, we established a dynamic inventory of vehicular HONO emissions in Jinniu District in Chengdu and further found the traditional estimation indicator would overestimate HONO emissions by around 17 %. Our findings would help to advance a deeper understanding of vehicular HONO emissions and the modified estimation indicator would be beneficial in minimizing the uncertainties of the HONO budget in the troposphere.

Deep learning enhancing guide RNA design for CRISPR/Cas12a-based diagnostics.

Rapid and accurate diagnostic tests are fundamental for improving patient outcomes and combating infectious diseases. The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) Cas12a-based detection system has emerged as a promising solution for on-site nucleic acid testing. Nonetheless, the effective design of CRISPR RNA (crRNA) for Cas12a-based detection remains challenging and time-consuming. In this study, we propose an enhanced crRNA design system with deep learning for Cas12a-mediated diagnostics, referred to as EasyDesign. This system employs an optimized convolutional neural network (CNN) prediction model, trained on a comprehensive data set comprising 11,496 experimentally validated Cas12a-based detection cases, encompassing a wide spectrum of prevalent pathogens, achieving Spearman's ρ = 0.812. We further assessed the model performance in crRNA design for four pathogens not included in the training data: Monkeypox Virus, Enterovirus 71, Coxsackievirus A16, and Listeria monocytogenes. The results demonstrated superior prediction performance compared to the traditional experiment screening. Furthermore, we have developed an interactive web server (https://crispr.zhejianglab.com/) that integrates EasyDesign with recombinase polymerase amplification (RPA) primer design, enhancing user accessibility. Through this web-based platform, we successfully designed optimal Cas12a crRNAs for six human papillomavirus (HPV) subtypes. Remarkably, all the top five predicted crRNAs for each HPV subtype exhibited robust fluorescent signals in CRISPR assays, thereby suggesting that the platform could effectively facilitate clinical sample testing. In conclusion, EasyDesign offers a rapid and reliable solution for crRNA design in Cas12a-based detection, which could serve as a valuable tool for clinical diagnostics and research applications.

TRIM35 Negatively Regulates the cGAS-STING-Mediated Signaling Pathway by Attenuating K63-Linked Ubiquitination of STING.

The cGAS-STING-mediated antiviral response plays an important role in the defense against DNA virus infection. Tripartite motif protein 35 (TRIM35), an E3 ubiquitin ligase, was identified as a positive regulator of RLR-mediated antiviral signaling in our previous study, but the effect of TRIM35 on the cGAS-STING signaling pathway has not been elucidated. Herein, we showed that TRIM35 negatively regulates the cGAS-STING signaling pathway by directly targeting STING. TRIM35 overexpression significantly inhibited the cGAMP-triggered phosphorylation of TBK1 and IRF3, attenuating IFN-ß expression and the downstream antiviral response. Mechanistically, TRIM35 colocalized and directly interacted with STING in the cytoplasm. TRM35 removed K63-linked ubiquitin from STING through the C36 and C44 sites in the RING domain, which impaired the interaction of STING with TBK1 or IKKε. In addition, we demonstrated that the RING domain is a key region for the antiviral effects of TIRM35. These results collectively indicate that TRIM35 negatively regulates type I interferon (IFN-I) production by targeting and deubiquitinating STING. TRIM35 may be a potential therapeutic target for controlling viral infection.

Breastfeeding may reduce the effects of maternal smoking on lung cancer mortality in adult offspring: a prospective cohort study.

BACKGROUND: Although previous research has indicated a correlation between smoking and the mortality rate in patients with lung cancer, the impact of early life factors on this relationship remains unclear and requires further investigation. This study aimed to investigate the hypothesis that breastfeeding reduces the risk of lung cancer-related death. METHODS: The authors conducted a prospective cohort study involving 501 859 participants recruited from the United Kingdom Biobank to explore the potential association between breastfeeding and the risk of lung cancer mortality using a Cox proportional hazards model. Subsequently, the polygenic risk score for lung cancer was calculated to detect interactions between genes and the environment. RESULTS: Over a median follow-up duration of 11.8 years, encompassing a total of 501 859 participants, breastfeeding was found to reduce the risk of lung cancer-related death and the impact of maternal smoking on lung cancer mortality in adult offspring. This association remained consistent after stratification. Furthermore, the influence of maternal smoking and breastfeeding on the risk of lung cancer mortality was significant at a high genetic risk level. CONCLUSION: Breastfeeding can reduce the risk of lung cancer-related death and the impact of maternal smoking on lung cancer mortality in adult offspring. This correlation has the potential to reduce the probability of lung-cancer-related deaths in subsequent generations.

Effective removal of Cu(II) from water by three-dimensional composite microspheres based on chitosan/sodium alginate/silicon dioxide: Adsorption performance and mechanism.

Chitosan (CS) is commonly used as an adsorbent for removing Cu(II) from water, but it has drawbacks such as solubility in dilute acid, difficulty in recycling in powder form, and short service life. This study utilized sodium alginate (SA) as a gel carrier to encapsulate CS, combined with silicon dioxide (SiO2) to improve mechanical stability. The preparation of CS/SA/SiO2 (SSC1.0) involved physical blending, CaCl2 cross-linking, and freeze-drying. Characterization methods such as SEM-EDS, FTIR, BET, and XRD were used to analyze the structural composition of SSC1.0. The material exhibited a folded surface, porous internal cross-section, nitrogen/oxygen-containing functional groups, and thermal stability in high temperatures and various aqueous environments. The adsorption performance of SSC1.0 on Cu(II) was evaluated under different conditions, showing a maximum adsorption capacity of 47.50 mg/g. The material maintained a removal rate above 70 % after 5 cycles. SSC1.0 also showed the highest removal rate of Cu(II) when applied to mine wastewater treatment. Adsorption modeling indicated that the process was driven by chemical reactions and was spontaneous and heat-absorbing.'

NXPH4 mediated by m5C contributes to the malignant characteristics of colorectal cancer via inhibiting HIF1A degradation.

OBJECTIVE: Colorectal cancer (CRC) is a form of malignancy that exhibits a comparatively elevated occurrence and fatality rate. Given the relatively slower progress in diagnostic and therapeutic approaches for CRC, there is a need to investigate more accurate and efficient biomarkers. METHODS: Core regulatory genes were screened using the TCGA database, and the expression of neurexophilin 4 (NXPH4) and its prognostic implications were validated using tissue microarray staining. The assessment of NXPH4 functions involved a range of experiments, including cellular, organoid, and murine models. Furthermore, a regulatory network between m5C, NXPH4, and HIF1A was established through several in vitro experiments. RESULTS: The overexpression of NXPH4 is associated with unfavorable prognoses in patients with CRC and hepatocellular carcinoma. Additionally, it facilitates the progression of malignant tumors both in laboratory settings and in living organisms of colorectal carcinoma. Our research also reveals that NXPH4 mRNA can avoid degradation through RNautophagy, relying on an m5C-dependent mechanism. Moreover, NXPH4 amplifies the HIF signaling pathway and stabilizes HIF1A by competitively binding to PHD4. CONCLUSIONS: NXPH4, regulated by m5C, promotes malignant tumor progression and regulates the HIF pathway. Consequently, targeting NXPH4 through molecular therapies could potentially serve as an efficacious therapeutic strategy for the management of CRC exhibiting elevated NXPH4 expression.

Regulating Electron-Phonon Coupling by Solid Additive for Efficient Organic Solar Cells.

Strong electron-phonon coupling can hinder exciton transport and induce undesirable non-radiative recombination, resulting in a shortened exciton diffusion distance and constrained exciton dissociation in organic solar cells (OSCs). Therefore, suppressing electron-phonon coupling is crucially important for achieve high-performance OSCs. Here, we employ the solid additive to regulating electron-phonon coupling in OSCs. The planar configuration of SA1 confers a significant advantage in suppressing lattice vibrations in the active layers, reducing the scattering of excitons by phonons caused by lattice vibrations. Consequently, a slow but sustained hole transfer process is identified in the SA1-assisted film, indicating an enhancement in hole transfer efficiency. Prolonged exciton diffusion length and exciton lifetime are achieved in the blend film processed with SA1, attributed to a low non-radiative recombination rate and low energetic disorder for charge carrier transport. As a result, a high efficiency of 20% was achieved for ternary device with a remarkable short-circuit current. This work highlights the important role of suppressing electron-phonon coupling in improving the photovoltaic performance of OSCs.

Encapsulation of Pd Single-Atom Sites in Zeolite for Highly Efficient Semihydrogenation of Alkynes.

Palladium (Pd)-based single-atom catalysts (SACs) have shown outstanding selectivity for semihydrogenation of alkynes, but most Pd single sites coordinated with highly electronegative atoms (such as N, O, and S) of supports will result in a decrease in the electron density of Pd sites, thereby weakening the adsorption of reactants and reducing catalytic performance. Constructing a rich outer-shell electron environment of Pd single-atom sites by changing the coordination structure offers a novel opportunity to enhance the catalytic efficiency with excellent alkene selectivity. Therefore, in this work, we first propose the in situ preparation of isolated Pd sites encapsulated within Al/Si-rich ZSM-5 structure using the one-pot seed-assisted growth method. Pd1@ZSM-5 features Pd-O-Al/Si bonds, which can boost the domination of d-electron near the Fermi level, thereby promoting the adsorption of substrates on Pd sites and reducing the energy barrier for the semihydrogenation of alkynes. In semihydrogenation of phenylacetylene, Pd1@ZSM-5 catalyst performs the highest turnover frequency (TOF) value of 33582 molC═C/molPd/h with 96% selectivity of styrene among the reported heterogeneous catalysts and nearly 17-fold higher than that of the commercial Lindlar catalyst (1992 molC═C/molPd/h). This remarkable catalytic performance can be retained even after 6 cycles of usage. Particularly, the zeolitic confinement structure of Pd1@ZSM-5 enables precise shape-selective catalysis for alkyne reactants with a size less than 4.3 Å.

Structural basis for the activity of the type VII CRISPR-Cas system.

The newly identified type VII CRISPR-Cas candidate system uses a CRISPR RNA-guided ribonucleoprotein complex formed by Cas5 and Cas7 proteins to target RNA1. However, the RNA cleavage is executed by a dedicated Cas14 nuclease, which is distinct from the effector nucleases of the other CRISPR-Cas systems. Here we report seven cryo-electron microscopy structures of the Cas14-bound interference complex at different functional states. Cas14, a tetrameric protein in solution, is recruited to the Cas5-Cas7 complex in a target RNA-dependent manner. The N-terminal catalytic domain of Cas14 binds a stretch of the substrate RNA for cleavage, whereas the C-terminal domain is primarily responsible for tethering Cas14 to the Cas5-Cas7 complex. The biochemical cleavage assays corroborate the captured functional conformations, revealing that Cas14 binds to different sites on the Cas5-Cas7 complex to execute individual cleavage events. Notably, a plugged-in arginine of Cas7 sandwiched by a C-shaped clamp of C-terminal domain precisely modulates Cas14 binding. More interestingly, target RNA cleavage is altered by a complementary protospacer flanking sequence at the 5' end, but not at the 3' end. Altogether, our study elucidates critical molecular details underlying the assembly of the interference complex and substrate cleavage in the type VII CRISPR-Cas system, which may help rational engineering of the type VII CRISPR-Cas system for biotechnological applications.