The structural analysis of the periplasmic domain of Sinorhizobium meliloti chemoreceptor McpZ reveals a novel fold and suggests a complex mechanism of transmembrane signaling

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dc.contributor.authorSalar, Safouraen
dc.contributor.authorBall, Nicolas E.en
dc.contributor.authorBaaziz, Hibaen
dc.contributor.authorNix, Jay C.en
dc.contributor.authorSobe, Richard C.en
dc.contributor.authorCompton, K. Karlen
dc.contributor.authorZhulin, Igor B.en
dc.contributor.authorBrown, Anne M.en
dc.contributor.authorScharf, Birgit E.en
dc.contributor.authorSchubot, Florian D.en
dc.date.accessioned2023-06-28T12:55:31Zen
dc.date.available2023-06-28T12:55:31Zen
dc.date.issued2023-05en
dc.description.abstractChemotaxis is a fundamental process whereby bacteria seek out nutrient sources and avoid harmful chemicals. For the symbiotic soil bacterium Sinorhizobium meliloti, the chemotaxis system also plays an essential role in the interaction with its legume host. The chemotactic signaling cascade is initiated through interactions of an attractant or repellent compound with chemoreceptors or methyl-accepting chemotaxis proteins (MCPs). S. meliloti possesses eight chemoreceptors to mediate chemotaxis. Six of these receptors are transmembrane proteins with periplasmic ligand-binding domains (LBDs). The specific functions of McpW and McpZ are still unknown. Here, we report the crystal structure of the periplasmic domain of McpZ (McpZPD) at 2.7 angstrom resolution. McpZPD assumes a novel fold consisting of three concatenated four-helix bundle modules. Through phylogenetic analyses, we discovered that this helical tri-modular domain fold arose within the Rhizobiaceae family and is still evolving rapidly. The structure, offering a rare view of a ligand-free dimeric MCP-LBD, reveals a novel dimerization interface. Molecular dynamics calculations suggest ligand binding will induce conformational changes that result in large horizontal helix movements within the membrane-proximal domains of the McpZPD dimer that are accompanied by a 5 angstrom vertical shift of the terminal helix toward the inner cell membrane. These results suggest a mechanism of transmembrane signaling for this family of MCPs that entails both piston-type and scissoring movements. The predicted movements terminate in a conformation that closely mirrors those observed in related ligand-bound MCP-LBDs.en
dc.description.notesNational Science Foundation; NIH Office of the Directoren
dc.description.sponsorshipNational Science Foundation; NIH Office of the Directoren
dc.description.versionPublished versionen
dc.format.mimetypeapplication/pdfen
dc.identifier.doihttps://doi.org/10.1002/prot.26510en
dc.identifier.eissn1097-0134en
dc.identifier.issn0887-3585en
dc.identifier.pmid37213073en
dc.identifier.urihttp://hdl.handle.net/10919/115555en
dc.language.isoenen
dc.publisherWileyen
dc.rightsCreative Commons Attribution-NonCommercial-NoDerivatives 4.0 Internationalen
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/en
dc.subjectchemotaxisen
dc.subjecthelical tri-modular sensor domainen
dc.subjectligand-binding domainen
dc.subjectmethyl-accepting chemotaxis proteinen
dc.subjectpistonen
dc.subjectscissoringen
dc.subjecttransmembrane signalingen
dc.titleThe structural analysis of the periplasmic domain of Sinorhizobium meliloti chemoreceptor McpZ reveals a novel fold and suggests a complex mechanism of transmembrane signalingen
dc.title.serialProteins-Structure Function and Bioinformaticsen
dc.typeArticle - Refereeden
dc.type.dcmitypeTexten

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