title: Heme-dependent autophosphorylation of a heme sensor kinase, ChrS, from Corynebacterium diphtheriae reconstituted in proteoliposomes.
abstract: Corynebacterium diphteriae employs the response regulator, ChrA, and the sensor kinase, ChrS, of a two-component signal transduction system to utilize host heme iron. Although ChrS is predicted to encode a heme sensor, the sensing mechanism remains to be characterized. In this report, ChrS expressed in Eshcherichia coli membranes was solubilized and purified using decylmaltoside. ChrS protein incorporated into proteoliposomes catalyzed heme-dependent autophosphorylation by ATP. Other metalloporphyrins and iron did not stimulate kinase activity. The UV-Vis spectrum of hemin in the ChrS-proteoliposomes indicated that heme directly interacts with ChrS. This is the first functional reconstitution of a bacterial heme-sensing protein.
authors.affiliation: Yokohama City University Graduate School of Nanobioscience, Suehiro, Tsurumi, Yokohama, Kanagawa, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ito
authors.forename: Shoko
authors.initials: S
authors.lastname: Nakagawa
authors.forename: Ayako
authors.initials: A
authors.lastname: Komagata
authors.forename: Masao
authors.initials: M
authors.lastname: Ikeda-Saito
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Shiro
authors.forename: Hiro
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D003353:Corynebacterium diphtheriae / Q000201:enzymology* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006418:Heme / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D011510:Proteolipids / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D011510:Proteolipids; C020485:proteoliposomes; D006418:Heme; D011494:Protein Kinases