Structural analysis of a putative SAM-dependent methyltransferase, YtqB, from Bacillus subtilis

Biochem Biophys Res Commun. 2014 Apr 18;446(4):921-6. doi: 10.1016/j.bbrc.2014.03.026. Epub 2014 Mar 14.

Abstract

S-adenosyl-L-methionine (SAM)-dependent methyltransferases (MTases) methylate diverse biological molecules using a SAM cofactor. The ytqB gene of Bacillus subtilis encodes a putative MTase and its biological function has never been characterized. To reveal the structural features and the cofactor binding mode of YtqB, we have determined the crystal structures of YtqB alone and in complex with its cofactor, SAM, at 1.9 Å and 2.2 Å resolutions, respectively. YtqB folds into a β-sheet sandwiched by two α-helical layers, and assembles into a dimeric form. Each YtqB monomer contains one SAM binding site, which shapes SAM into a slightly curved conformation and exposes the reactive methyl group of SAM potentially to a substrate. Our comparative structural analysis of YtqB and its homologues indicates that YtqB is a SAM-dependent class I MTase, and provides insights into the substrate binding site of YtqB.

Keywords: Bacillus subtilis; Crystal structure; Methyltransferase; S-adenosyl-l-methionine; YtqB.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacillus subtilis / chemistry
  • Bacillus subtilis / enzymology*
  • Bacillus subtilis / metabolism
  • Binding Sites
  • Crystallography, X-Ray
  • Methyltransferases / chemistry*
  • Methyltransferases / metabolism*
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Conformation
  • Protein Multimerization
  • S-Adenosylmethionine / chemistry
  • S-Adenosylmethionine / metabolism*
  • Sequence Alignment

Substances

  • S-Adenosylmethionine
  • Methyltransferases

Associated data

  • PDB/4PON
  • PDB/4POO