8htf
From Proteopedia
Crystal structure of an effector in complex with ubiquitin
Structural highlights
FunctionCTEC_CHRVO ADP-ribosyltransferase that specifically modifies host ubiquitin on 'Thr-66' residue, which causes the shutdown of polyubiquitin synthesis and disrupts the recognition and reversal of polyubiquitin in host cells during infection (PubMed:32330457). Threonine ADP-ribosylation of ubiquitin prevents the transfer of ubiquitin from ubiquitin-activating enzyme E1 to ubiquitin-conjugating enzyme E2, which inhibits subsequent ubiquitin activation and leads to the shutdown of polyubiquitin synthesis in host cells (PubMed:32330457). The modification also causes dysfunction of polyubiquitin chains in cells, thereby blocking host ubiquitin signaling (PubMed:32330457). ADP-ribosylation by CteC is likely irreversible (PubMed:32330457). Plays a crucial role in bacterial colonization in mice during infection (PubMed:32330457).[1] Publication Abstract from PubMedUbiquitination plays essential roles in eukaryotic cellular processes. The effector protein CteC from Chromobacterium violaceum blocks host ubiquitination by mono-ADP-ribosylation of ubiquitin (Ub) at residue T66. However, the structural basis for this modification is unknown. Here we report three crystal structures of CteC in complexes with Ub, NAD(+) or ADP-ribosylated Ub, which represent different catalytic states of CteC in the modification. CteC adopts a special 'D-E' catalytic motif for catalysis and binds NAD(+) in a half-ligand binding mode. The specific recognition of Ub by CteC is determined by a relatively separate Ub-targeting domain and a long loop L6, not the classic ADP-ribosylating turn-turn loop. Structural analyses with biochemical results reveal that CteC represents a large family of poly (ADP-ribose) polymerase (PARP)-like ADP-ribosyltransferases, which harbors chimeric features from the R-S-E and H-Y-E classes of ADP-ribosyltransferases. The family of CteC-like ADP-ribosyltransferases has a common 'D-E' catalytic consensus and exists extensively in bacteria and eukaryotic microorganisms. Molecular basis of threonine ADP-ribosylation of ubiquitin by bacterial ARTs.,Tan J, Xu Y, Wang X, Yan F, Xian W, Liu X, Chen Y, Zhu Y, Zhou Y Nat Chem Biol. 2024 Apr;20(4):463-472. doi: 10.1038/s41589-023-01475-3. Epub 2023 , Nov 9. PMID:37945894[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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