7vmc
Crystal structure of EF-Tu/CdiA/CdiICrystal structure of EF-Tu/CdiA/CdiI
Structural highlights
FunctionEFTU2_ECOLI This protein promotes the GTP-dependent binding of aminoacyl-tRNA to the A-site of ribosomes during protein biosynthesis.[HAMAP-Rule:MF_00118] May play an important regulatory role in cell growth and in the bacterial response to nutrient deprivation.[HAMAP-Rule:MF_00118] Publication Abstract from PubMedContact-dependent growth inhibition is a mechanism of interbacterial competition mediated by delivery of the C-terminal toxin domain of CdiA protein (CdiA-CT) into neighboring bacteria. The CdiA-CT of enterohemorrhagic Escherichia coli EC869 (CdiA-CTEC869) cleaves the 3'-acceptor regions of specific tRNAs in a reaction that requires the translation factors Tu/Ts and GTP. Here, we show that CdiA-CTEC869 has an intrinsic ability to recognize a specific sequence in substrate tRNAs, and Tu:Ts complex promotes tRNA cleavage by CdiA-CTEC869. Uncharged and aminoacylated tRNAs (aa-tRNAs) were cleaved by CdiA-CTEC869 to the same extent in the presence of Tu/Ts, and the CdiA-CTEC869:Tu:Ts:tRNA(aa-tRNA) complex formed in the presence of GTP. CdiA-CTEC869 interacts with domain II of Tu, thereby preventing the 3'-moiety of tRNA to bind to Tu as in canonical Tu:GTP:aa-tRNA complexes. Superimposition of the Tu:GTP:aa-tRNA structure onto the CdiA-CTEC869:Tu structure suggests that the 3'-portion of tRNA relocates into the CdiA-CTEC869 active site, located on the opposite side to the CdiA-CTEC869 :Tu interface, for tRNA cleavage. Thus, CdiA-CTEC869 is recruited to Tu:GTP:Ts, and CdiA-CT:Tu:GTP:Ts recognizes substrate tRNAs and cleaves them. Tu:GTP:Ts serves as a reaction scaffold that increases the affinity of CdiA-CTEC869 for substrate tRNAs and induces a structural change of tRNAs for efficient cleavage by CdiA-CTEC869. Mechanistic insights into tRNA cleavage by a contact-dependent growth inhibitor protein and translation factors.,Wang J, Yashiro Y, Sakaguchi Y, Suzuki T, Tomita K Nucleic Acids Res. 2022 May 6;50(8):4713-4731. doi: 10.1093/nar/gkac228. PMID:35411396[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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