4fme | pdb_00004fme
EspG-Rab1-Arf6 complex
Structural highlights
Function[ARF6_HUMAN] GTP-binding protein involved in protein trafficking; regulates endocytic recycling and cytoskeleton remodeling. May modulate vesicle budding and uncoating within the Golgi apparatus. Functions as an allosteric activator of the cholera toxin catalytic subunit, an ADP-ribosyltransferase. Involved in the regulation of dendritic spine development (By similarity). Contributes to the regulation of dendritic branching and filopodia extension.[1] [2] [3] [RAB1A_HUMAN] Probably required for transit of protein from the ER through Golgi compartment. Binds GTP and GDP and possesses intrinsic GTPase activity. Publication Abstract from PubMedRab GTPases are frequent targets of vacuole-living bacterial pathogens for appropriate trafficking of the vacuole. Here we discover that bacterial effectors including VirA from nonvacuole Shigella flexneri and EspG from extracellular Enteropathogenic Escherichia coli (EPEC) harbor TBC-like dual-finger motifs and exhibits potent RabGAP activities. Specific inactivation of Rab1 by VirA/EspG disrupts ER-to-Golgi trafficking. S. flexneri intracellular persistence requires VirA TBC-like GAP activity that mediates bacterial escape from autophagy-mediated host defense. Rab1 inactivation by EspG severely blocks host secretory pathway, resulting in inhibited interleukin-8 secretion from infected cells. Crystal structures of VirA/EspG-Rab1-GDP-aluminum fluoride complexes highlight TBC-like catalytic role for the arginine and glutamine finger residues and reveal a 3D architecture distinct from that of the TBC domain. Structure of Arf6-EspG-Rab1 ternary complex illustrates a pathogenic signaling complex that rewires host Arf signaling to Rab1 inactivation. Structural distinctions of VirA/EspG further predict a possible extensive presence of TBC-like RabGAP effectors in counteracting various host defenses. Structurally Distinct Bacterial TBC-like GAPs Link Arf GTPase to Rab1 Inactivation to Counteract Host Defenses.,Dong N, Zhu Y, Lu Q, Hu L, Zheng Y, Shao F Cell. 2012 Aug 31;150(5):1029-41. PMID:22939626[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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