title: Expression, purification, crystallization and preliminary X-ray diffraction studies of the cmcI component of Streptomyces clavuligerus 7alpha-cephem-methoxylase.
abstract: Cephamycins are broad-spectrum beta-lactam antibiotics that show resistance to certain forms of beta-lactamases. They differ from cephalosporins by the presence of a methoxyl group at the C-7alpha position. The gene products of cmcI and cmcJ are believed to control 7alpha-methoxylation of cephalosporins through successive steps of hydroxylation and methylation. Here, the expression, purification, crystallization and initial data-collection statistics of the 236-amino-acid protein product of cmcI from Streptomyces clavuligerus is reported. The crystals belong to space group P2(1), with unit-cell parameters a = 93.6, b = 182.6, c = 103.2 A, beta = 91.05 degrees. Diffraction data were collected to 2.5 A.
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University, Box 596, S-751 24 Uppsala, Sweden. diane@xray.bmc.uu.se
authors.forename: Diane R
authors.initials: DR
authors.lastname: Lester
authors.forename: Linda M
authors.initials: LM
authors.lastname: Oster
authors.forename: Martin
authors.initials: M
authors.lastname: Svenda
authors.forename: Inger
authors.initials: I
authors.lastname: Andersson
mesh_terms: D003460:Crystallization; D004269:DNA, Bacterial / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D008780:Methyltransferases / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D011487:Protein Conformation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D021241:Spectrometry, Mass, Electrospray Ionization; D013302:Streptomyces / Q000737:chemistry / Q000201:enzymology*; D014961:X-Ray Diffraction
chemical_list: D004269:DNA, Bacterial; D009097:Multienzyme Complexes; C093122:7-alpha-cephem-methoxylase; D006899:Mixed Function Oxygenases; D008780:Methyltransferases