5izv
From Proteopedia
Crystal structure of the legionella pneumophila effector protein RavZ - F222
Structural highlights
FunctionRAVZ_LEGPH Cysteine protease effector that inhibits host cell autophagy by targeting lipid-conjugated ATG8 family proteins on pre-autophagosomal structures (PubMed:23112293, PubMed:29458288, PubMed:32686895, PubMed:31722778, PubMed:31719622, PubMed:33298241, PubMed:26343456, PubMed:28395732). Specifically hydrolyzes the amide bond between the C-terminal glycine residue and an adjacent aromatic residue in ATG8 proteins conjugated to phosphatidylethanolamine (PE), producing an ATG8 protein that cannot be reconjugated by host ATG7 and ATG3 (PubMed:23112293, PubMed:29458288, PubMed:32686895, PubMed:26343456, PubMed:28395732). Mechanistically, Ravz interacts with ATG8 proteins conjugated to PE via its LIR motifs, extracts them from the membrane of autophagosomes and integrates the PE part into its own lipid-binding site (PubMed:28395732). It then removes the lipid component of the ATG8 protein (PubMed:28395732). Also able to mediate delipidation of ATG8 proteins conjugated to phosphatidylserine (PS) during non-canonical autophagy (PubMed:33909989). Inhibits host ubiquitin recruitment to bacteria-containing vacuoles, suggesting that it is able to mediate delipidation of other proteins in addition to ATG8 proteins (PubMed:28971069). It is however not involved in the exclusion of autophagy adapters from bacteria-containing vacuoles decorated with ubiquitin (PubMed:32482642).[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] Publication Abstract from PubMedHosts utilize macroautophagy/autophagy to clear invading bacteria; however, bacteria have also developed a specific mechanism to survive by manipulating the host cell autophagy mechanism. One pathogen, Legionella pneumophila, can hinder host cell autophagy by using the specific effector protein RavZ that cleaves phosphatidylethanolamine-conjugated LC3 on the phagophore membrane. However, the detailed molecular mechanisms associated with the function of RavZ have hitherto remained unclear. Here, we report on the biochemical characteristics of the RavZ-LC3 interaction, the solution structure of the 1:2 complex between RavZ and LC3, and crystal structures of RavZ showing different conformations of the active site loop without LC3. Based on our biochemical, structural, and cell-based analyses of RavZ and LC3, both distant flexible N- and C-terminal regions containing LC3-interacting region (LIR) motifs are important for substrate recognition. These results suggest a novel mechanism of RavZ action on the phagophore membrane and lay the groundwork for understanding how bacterial pathogens can survive autophagy. The 1:2 complex between RavZ and LC3 reveals a mechanism for deconjugation of LC3 on the phagophore membrane.,Kwon DH, Kim S, Jung YO, Roh KH, Kim L, Kim BW, Hong SB, Lee IY, Song JH, Lee WC, Choi EJ, Hwang KY, Song HK Autophagy. 2017 Jan 2;13(1):70-81. doi: 10.1080/15548627.2016.1243199. Epub 2016 , Oct 28. PMID:27791457[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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