Mechanism of activation of contact-dependent growth inhibition tRNase toxin by the amino acid biogenesis factor CysK in the bacterial competition system.
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引用次数: 0
Abstract
Contact-dependent growth inhibition (CDI) is a bacterial competition mechanism, wherein the C-terminal toxin domain of CdiA protein (CdiA-CT) is transferred from one bacterium to another, impeding the growth of the toxin recipient. In uropathogenic Escherichia coli 536, CdiA-CT (CdiA-CTEC536) is a tRNA anticodon endonuclease that requires a cysteine biogenesis factor, CysK, for its activity. However, the mechanism underlying tRNA recognition and cleavage by CdiA-CTEC536 remains unresolved. Here, we present the cryo-EM structure of the CysK:CdiA-CTEC536:tRNA ternary complex. The interaction between CdiA-CTEC536 and CysK stabilizes the CdiA-CTEC536 structure and facilitates tRNA binding and the formation of the CdiA-CTEC536 catalytic core structure. The bottom-half of the tRNA interacts exclusively with CdiA-CTEC536 and the α-helices of CdiA-CTEC536 engage with the minor and major grooves of the bottom-half of tRNA, positioning the tRNA anticodon loop at the CdiA-CTEC536 catalytic site for tRNA cleavage. Thus, CysK serves as a platform facilitating the recognition and cleavage of substrate tRNAs by CdiA-CTEC536.
期刊介绍:
Nucleic Acids Research (NAR) is a scientific journal that publishes research on various aspects of nucleic acids and proteins involved in nucleic acid metabolism and interactions. It covers areas such as chemistry and synthetic biology, computational biology, gene regulation, chromatin and epigenetics, genome integrity, repair and replication, genomics, molecular biology, nucleic acid enzymes, RNA, and structural biology. The journal also includes a Survey and Summary section for brief reviews. Additionally, each year, the first issue is dedicated to biological databases, and an issue in July focuses on web-based software resources for the biological community. Nucleic Acids Research is indexed by several services including Abstracts on Hygiene and Communicable Diseases, Animal Breeding Abstracts, Agricultural Engineering Abstracts, Agbiotech News and Information, BIOSIS Previews, CAB Abstracts, and EMBASE.