Protein Family Models

This is a family of related homocysteine S-methyltransferases enzymes: 5-methyltetrahydrofolate--homocysteine S-methyltransferases also known EC:2.1.1.13, [2]; Betaine--homocysteine S-methyltransferase (vitamin B12 dependent), EC:2.1.1.5, [3]; and Homocysteine S-methyltransferase, EC:2.1.1.10, [1]. [1]. 9882684. S-methylmethionine metabolism in Escherichia coli. Thanbichler M, Neuhierl B, Bock A;. J Bacteriol 1999;181:662-665. [2]. 9013615. Human methionine synthase. cDNA cloning, gene localization, and expression. Chen LH, Liu ML, Hwang HY, Chen LS, Korenberg J, Shane B;. J Biol Chem 1997;272:3628-3634. [3]. 8798461. Purification, kinetic properties, and cDNA cloning of mammalian betaine-homocysteine methyltransferase. Garrow TA;. J Biol Chem 1996;271:22831-22838. (from Pfam)

Date:

2024-10-16

This B12 binding domain is found in methionine synthase EC:2.1.1.13 Swiss:Q99707, and other shorter proteins that bind to B12. This domain is always found to the N-terminus of Pfam:PF02310. The structure of this domain is known [1], it is a 4 helix bundle. Many of the conserved residues in this domain are involved in B12 binding, such as those in the MXXVG motif. [1]. 7992050. How a protein binds B12: A 3.0 A X-ray structure of B12-binding domains of methionine synthase. Drennan CL, Huang S, Drummond JT, Matthews RG, Lidwig ML;. Science 1994;266:1669-1674. (from Pfam)

Date:

2024-10-16

This domain binds to B12 (adenosylcobamide)[1-3], it is found in several enzymes, such as glutamate mutase Swiss:Q05488, methionine synthase Swiss:Q99707 and methylmalonyl-CoA mutase Swiss:P22033. It contains a conserved DxHxxGx(41)SxVx(26)GG motif, which is important for B12 binding [2]. [1]. 9739092. How a protein prepares for B12 binding: structure and dynamics of the B12-binding subunit of glutamate mutase from Clostridium tetanomorphum. Tollinger M, Konrat R, Hilbert BH, Marsh EN, Krautler B;. Structure 1998;6:1021-1033. [2]. 11914353. Role for vitamin B(12) in light induction of gene expression in the bacterium Myxococcus xanthus. Cervantes M, Murillo FJ;. J Bacteriol. 2002;184:2215-2224. [3]. 18315685. Vitamin B12 partners the CarH repressor to downregulate a photoinducible promoter in Myxococcus xanthus. Perez-Marin MC, Padmanabhan S, Polanco MC, Murillo FJ, Elias-Arnanz M;. Mol Microbiol. 2008;67:804-819. (from Pfam)

Date:

2024-10-16

This family includes a variety of pterin binding enzymes that all adopt a TIM barrel fold. The family includes dihydropteroate synthase EC:2.5.1.15 as well as a group methyltransferase enzymes including methyltetrahydrofolate, corrinoid iron-sulfur protein methyltransferase (MeTr) Swiss:Q46389 that catalyses a key step in the Wood-Ljungdahl pathway of carbon dioxide fixation. It transfers the N5-methyl group from methyltetrahydrofolate (CH3-H4folate) to a cob(I)amide centre in another protein, the corrinoid iron-sulfur protein. MeTr is a member of a family of proteins that includes methionine synthase and methanogenic enzymes that activate the methyl group of methyltetra-hydromethano(or -sarcino)pterin [2]. [1]. 9187658. Crystal structure of the anti-bacterial sulfonamide drug target dihydropteroate synthase. Achari A, Somers DO, Champness JN, Bryant PK, Rosemond J, Stammers DK. Nat Struct Biol 1997;4:490-497. This paper shows similarity by sequence of DHPS and MetH enzymes. [2]. 10997901. Crystal structure of a methyltetrahydrofolate- and corrinoid-dependent methyltransferase. Doukov T, Seravalli J, Stezowski JJ, Ragsdale SW;. Structure Fold Des 2000;8:817-830. (from Pfam)

Date:

2024-10-16

This family represents 5-methyltetrahydrofolate--homocysteine methyltransferase (EC 2.1.1.13), one of at least three different enzymes able to convert homocysteine to methionine by transferring a methyl group on to the sulfur atom. It is also called the vitamin B12(or cobalamine)-dependent methionine synthase. Other methionine synthases include 5-methyltetrahydropteroyltriglutamate--homocysteine S-methyltransferase (MetE, EC 2.1.1.14, the cobalamin-independent methionine synthase) and betaine-homocysteine methyltransferase.

Gene:

metH

Date:

2024-05-30