title: Crystal structure of Rv2118c: an AdoMet-dependent methyltransferase from Mycobacterium tuberculosis H37Rv.
abstract: Rv2118c belongs to the class of conserved hypothetical proteins from Mycobacterium tuberculosis H37Rv. The crystal structure of Rv2118c in complex with S-adenosyl-l-methionine (AdoMet) has been determined at 1.98 A resolution. The crystallographic asymmetric unit consists of a monomer, but symmetry-related subunits interact extensively, leading to a tetrameric structure. The structure of the monomer can be divided functionally into two domains: the larger catalytic C-terminal domain that binds the cofactor AdoMet and is involved in the transfer of methyl group from AdoMet to the substrate and a smaller N-terminal domain. The structure of the catalytic domain is very similar to that of other AdoMet-dependent methyltransferases. The N-terminal domain is primarily a beta-structure with a fold not found in other methyltransferases of known structure. Database searches reveal a conserved family of Rv2118c-like proteins from various organisms. Multiple sequence alignments show several regions of high sequence similarity (motifs) in this family of proteins. Structure analysis and homology to yeast Gcd14p suggest that Rv2118c could be an RNA methyltransferase, but further studies are required to establish its functional role conclusively.
authors.affiliation: Molecular and Structural Biology Division, Central Drug Research Institute, Chattar Manzil Palace, Mahatma Gandhi Marg, Lucknow 226001, India.
authors.forename: A
authors.initials: A
authors.lastname: Gupta
authors.forename: P H
authors.initials: PH
authors.lastname: Kumar
authors.forename: T K
authors.initials: TK
authors.lastname: Dineshkumar
authors.forename: U
authors.initials: U
authors.lastname: Varshney
authors.forename: H S
authors.initials: HS
authors.lastname: Subramanya
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001665:Binding Sites; D020134:Catalytic Domain; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D005656:Fungal Proteins / Q000737:chemistry; D008780:Methyltransferases / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000201:enzymology*; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry; D012436:S-Adenosylmethionine / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D055672:Static Electricity; D012359:tRNA Methyltransferases
chemical_list: D005656:Fungal Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D012436:S-Adenosylmethionine; D008780:Methyltransferases; D012359:tRNA Methyltransferases; C119384:GCD14 protein, S cerevisiae