title: Purification, crystallization and preliminary crystallographic analysis of the 23S rRNA methyltransferase RlmM (Cm2498) from Escherichia coli.
abstract: RlmM is an AdoMet-dependent methyltransferase that is responsible for 2'-O-methylation of C2498 in the peptidyl-transferase loop of bacterial 23S rRNA. This modification occurs before assembly of the 50S ribosomal subunit, and lack of C2498 methylation can cause a slight reduction in bacterial fitness. Here, the purification and crystallization of RlmM from Escherichia coli as well as its preliminary crystallographic analysis are presented. Cocrystallization of RlmM with AdoMet was carried out and X-ray diffraction data were collected to a resolution of 2.30 Å on beamline BL17U at the SSRF. However, electron density for AdoMet cannot be observed by comprehensive crystallographic analysis, indicating that it is not bound by RlmM during the cocrystallization process. The structure was solved by molecular replacement and refinement is in progress. The crystal contained one molecule in the asymmetric unit and belonged to space group P2(1), with unit-cell parameters a = 56.07, b = 59.38, c = 54.35 Å, β = 94.84°, which differs from the P3(1) or P3(1)21 space groups of previously reported RlmM structures (PDB entries 4auk, 4atn and 4b17).
authors.affiliation: College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
authors.forename: Hong Yue
authors.initials: HY
authors.lastname: Guo
authors.forename: Zeng Qiang
authors.initials: ZQ
authors.lastname: Gao
authors.forename: Heng
authors.initials: H
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Wei
authors.forename: Jian Hua
authors.initials: JH
authors.lastname: Xu
authors.forename: Wen Ya
authors.initials: WY
authors.lastname: Wang
authors.forename: Ai Xia
authors.initials: AX
authors.lastname: Yan
authors.forename: Yu Hui
authors.initials: YH
authors.lastname: Dong
mesh_terms: D018360:Crystallography, X-Ray; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000302:isolation & purification*; D008780:Methyltransferases / Q000737:chemistry* / Q000302:isolation & purification*; D012338:RNA, Ribosomal, 23S / Q000737:chemistry / Q000302:isolation & purification; D014961:X-Ray Diffraction
chemical_list: D029968:Escherichia coli Proteins; D012338:RNA, Ribosomal, 23S; D008780:Methyltransferases; C577634:RlmM protein, E coli; C035181:rRNA (adenosine-O-2'-)methyltransferase
keywords: AdoMet; RNA modification; RlmM; methyltransferases