title: Crystal structure of SAM-dependent O-methyltransferase from pathogenic bacterium Leptospira interrogans.
abstract: The S-adenosylmethionine (SAM)-dependent O-methyltransferase from Leptospira interrogans (LiOMT) expressed by gene LA0415 belongs to the Methyltransf_3 family (Pfam PF01596). In this family all of the five bacterial homologues with known function are reported as SAM-dependent O-methylstransferases involved in antibiotic production. The crystal structure of LiOMT in complex with S-adenosylhomocysteine reported here is the first bacterial protein structure in this family. The LiOMT structure shows a conserved SAM-binding region and a probable metal-dependent catalytic site. The molecules of LiOMT generate homodimers by N-terminal swapping, which assists the pre-organization of the substrate-binding site. Based on the sequence and structural analysis, it is implied by the catalytic and substrate-binding site that the substrate of LiOMT is a phenolic derivative, which probably has a large ring-shaped moiety.
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, PR China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Hou
authors.forename: Yanli
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhongwei
authors.initials: Z
authors.lastname: Zhou
authors.forename: Shilai
authors.initials: S
authors.lastname: Bao
authors.forename: Yajing
authors.initials: Y
authors.lastname: Lin
authors.forename: Weimin
authors.initials: W
authors.lastname: Gong
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007921:Leptospira interrogans / Q000201:enzymology*; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011497:Protein O-Methyltransferase / Q000737:chemistry*; D012436:S-Adenosylmethionine / Q000737:chemistry*; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D012436:S-Adenosylmethionine; D011497:Protein O-Methyltransferase