Methyltransferase involved in methanogenesis from methylated-thiols. Catalyzes two successive steps: mediates the transfer of a methyl group from the substrate to the cobalt cofactor of a methylated-thiol-specific corrinoid protein (MtsB), and the subsequent transfer of the methyl group from the corrinoid protein to coenzyme M. coenzyme M + methanethiol = H+ + hydrogen sulfide + methyl-coenzyme.

MVSEMTPTRRVMAAVLGGRVDYVPPANPLAQTTTELMQICNASWPKAHFDSKMMADLAAA PYEICGIEAARPQFDISLEAEVLGCKLDWNKPDRPPVTGPAYTDPADITWPDNLEEAGRI PVVLGAIEELRKRYDGMLPVIPVLTSPFTVAGHIAGVENLVRWTKTDPEKAHAFIEAATD FVIAYGKLQTAYGAHILFPADPSASGDLISGETYKEFVLPAHKRMAKEISCPLILHICGD TSKLLPYIKQSGIDCFSFDAVPVWYCRQVMGNEMSILGSLDVIDLMPNGTPEQVYNRTRE CILQGADIVGTACDVSFGTSLENLRAYVRACKETPIPKYDDVEDIIRQIGVGIGRNMKEN VLGGMQK373

	PMID	Title & Author	Abstract	Year
0	11073950	The MtsA subunit of the methylthiol:coenzyme M methyltransferase of Methanosarcina barkeri catalyses both half-reactions of corrinoid-dependent dimethylsulfide: coenzyme M methyl transfer. T C Tallant , L Paul, J A Krzycki	Methanogenesis from dimethylsulfide requires the intermediate methylation of coenzyme M. This reaction is catalyzed by a methylthiol:coenzyme M methyltransferase composed of two polypeptides, MtsA (a methylcobalamin:coenzyme M methyltransferase) and MtsB (homologous to a class of corrinoid proteins involved in methanogenesis). Recombinant MtsA was purified and found to be a homodimer that bound one zinc atom per polypeptide, but no corrinoid cofactor. MtsA is an active methylcobalamin:coenzyme M methyltransferase, but also methylates cob(I)alamin with dimethylsulfide, yielding equimolar methylcobalamin and methanethiol in an endergonic reaction with a K(eq) of 5 x 10(-)(4). MtsA and cob(I)alamin mediate dimethylsulfide:coenzyme M methyl transfer in the complete absence of MtsB. Dimethylsulfide inhibited methylcobalamin:coenzyme methyl transfer by MtsA. Inhibition by dimethylsulfide was mixed with respect to methylcobalamin, but competitive with coenzyme M. MtbA, a MtsA homolog participating in coenzyme M methylation with methylamines, was not inhibited by dimethylsulfide and did not catalyze detectable dimethylsulfide:cob(I)alamin methyl transfer. These results are most consistent with a model for the native methylthiol:coenzyme M methyltransferase in which MtsA mediates the methylation of corrinoid bound to MtsB with dimethylsulfide and subsequently demethylates MtsB-bound corrinoid with coenzyme M, possibly employing elements of the same methyltransferase active site for both reactions.	2001
1	18364240	Lipoprotein MtsA of MtsABC in Streptococcus pyogenes primarily binds ferrous ion with bicarbonate as a synergistic anion. Xuesong Sun , Ruiguang Ge, Jen-Fu Chiu, Hongzhe Sun, Qing-Yu He	Lipoprotein MtsA is a critical component of MtsABC responsible for iron binding and transport in the Gram-positive bacterium Streptococcus pyogenes. The present collective experimental data establish that Fe(2+) is the primary binding ion for MtsA under optimal physiologically relevant conditions. The binding affinities of MtsA to metal ions are Fe(2+)>Fe(3+)>Cu(2+)>Mn(2+)>Zn(2+). We report for the first time that bicarbonate is required as a synergistic anion for stable ferrous binding to MtsA, similar to the iron binding in human transferrin. This work provides valuable information, which helps to understand iron metabolism in bacteria, and creates a basis for developing strategies to suppress bacterial infection.	2008

Tallant T C , Paul L , Krzycki J A . The MtsA Subunit of the Methylthiol:Coenzyme M Methyltransferase of Methanosarcina barkeri, Catalyses Both Half-reactions of Corrinoid-dependent Dimethylsulfide: Coenzyme M Methyl Transfer *[J]. Journal of Biological Chemistry, 2001, 276.