6q7l
Spiral structure of E. coli RavA in the RavA-LdcI cage-like complex
Structural highlights
FunctionLDCI_ECOLI Plays a role in pH homeostasis by consuming protons and neutralizing the acidic by-products of carbohydrate fermentation. Publication Abstract from PubMedThe hexameric MoxR AAA+ ATPase RavA and the decameric lysine decarboxylase LdcI form a 3.3 MDa cage, proposed to assist assembly of specific respiratory complexes in E. coli. Here, we show that inside the LdcI-RavA cage, RavA hexamers adopt an asymmetric spiral conformation in which the nucleotide-free seam is constrained to two opposite orientations. Cryo-EM reconstructions of free RavA reveal two co-existing structural states: an asymmetric spiral, and a flat C2-symmetric closed ring characterised by two nucleotide-free seams. The closed ring RavA state bears close structural similarity to the pseudo two-fold symmetric crystal structure of the AAA+ unfoldase ClpX, suggesting a common ATPase mechanism. Based on these structures, and in light of the current knowledge regarding AAA+ ATPases, we propose different scenarios for the ATP hydrolysis cycle of free RavA and the LdcI-RavA cage-like complex, and extend the comparison to other AAA+ ATPases of clade 7. Structural insights into ATP hydrolysis by the MoxR ATPase RavA and the LdcI-RavA cage-like complex.,Jessop M, Arragain B, Miras R, Fraudeau A, Huard K, Bacia-Verloop M, Catty P, Felix J, Malet H, Gutsche I Commun Biol. 2020 Jan 28;3(1):46. doi: 10.1038/s42003-020-0772-0. PMID:31992852[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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