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          Institute: MPI für bioanorganische Chemie     Collection: MPI für bioanorganische Chemie     Display Documents

ID: 682093.0, MPI für bioanorganische Chemie / MPI für bioanorganische Chemie
A Heme-based Redox Sensor in the Methanogenic Archaeon Methanosarcina acetivorans
Authors:Molitor, Bastian; Stassen, Marc; Modi, Anuja; El-Mashtoly, Samir F.; Laurich, Christoph; Lubitz, Wolfgang; Dawson, John H.; Rother, Michael; Frankenberg-Dinkel, Nicole
Date of Publication (YYYY-MM-DD):2013
Title of Journal:Journal of Biological Chemistry
Journal Abbrev.:J. Biol. Chem.
Start Page:18458
End Page:18472
Review Status:Peer-review
Audience:Experts Only
Abstract / Description:Based on a bioinformatics study, the protein MA4561 from the methanogenic archaeon Methanosarcina acetivorans was originally predicted to be a multidomain phytochrome-like photosensory kinase possibly binding open-chain tetrapyrroles. Although we were able to show that recombinantly produced and purified protein does not bind any known phytochrome chromophores, UV-visible spectroscopy revealed the presence of a heme tetrapyrrole cofactor. In contrast to many other known cytoplasmic heme-containing proteins, the heme was covalently attached via one vinyl side chain to cysteine 656 in the second GAF domain. This GAF domain by itself is sufficient for covalent attachment. Resonance Raman and magnetic circular dichroism data support a model of a six-coordinate heme species with additional features of a five-coordination structure. The heme cofactor is redox-active and able to coordinate various ligands like imidazole, dimethyl sulfide, and carbon monoxide depending on the redox state. Interestingly, the redox state of the heme cofactor has a substantial influence on autophosphorylation activity. Although reduced protein does not autophosphorylate, oxidized protein gives a strong autophosphorylation signal independent from bound external ligands. Based on its genomic localization, MA4561 is most likely a sensor kinase of a two-component system effecting regulation of the Mts system, a set of three homologous corrinoid/methyltransferase fusion protein isoforms involved in methyl sulfide metabolism. Consistent with this prediction, an M. acetivorans mutant devoid of MA4561 constitutively synthesized MtsF. On the basis of our results, we postulate a heme-based redox/dimethyl sulfide sensory function of MA4561 and propose to designate it MsmS (methyl sulfide methyltransferase-associated sensor).
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für bioanorganische Chemie
External Affiliations:Molitor, B.; El-Mashtoly, S.F.; Frankenberg-Dinkel, N.; Ruhr Univ Bochum, Fac Biol & Biotechnol, D-44780 Bochum, Germany.
Stassen, M.; Rother, M.; Göthe Univ Frankfurt, Inst Mol Biosci, D-60438 Frankfurt, Germany.
Modi, A.; Dawson, J.H.; Univ S Carolina, Dept Chem & Biochem, Columbia, SC 29208 USA.
Rother, M.; Tech Univ Dresden, Inst Microbiol, D-01217 Dresden, Germany.
Identifiers:ISI:000320721900048 [ID No:1]
ISSN:0021-9258 [ID No:2]
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