title: Expression, crystallization and preliminary characterization of methylmalonyl coenzyme A epimerase from Propionibacterium shermanii.
abstract: Methylmalonyl-CoA epimerase (MMCE) is an enzyme that interconverts the R and S epimers of methylmalonyl-CoA in the pathway that links propionyl-CoA with succinyl-CoA. This is used for both biosynthetic and degradative processes, including the breakdown of odd-numbered fatty acids and some amino acids. The enzyme has been expressed in Escherichia coli both as the native enzyme and as its selenomethionine (SeMet) derivative. Crystals of both forms have been obtained by vapour diffusion using monomethylether PEG 2000 as precipitant. The native MMCE crystals are orthorhombic, with unit-cell parameters a = 56.0, b = 114.0, c = 156.0 A, and the SeMet-MMCE crystals are monoclinic, with unit-cell parameters a = 43.6, b = 78.6, c = 89.4 A, beta = 92.0 degrees; both diffract to better than 2.8 A resolution.
authors.affiliation: School of Biological Sciences, University of Auckland, Auckland, New Zealand.
authors.forename: A A
authors.initials: AA
authors.lastname: McCarthy
authors.forename: H M
authors.initials: HM
authors.lastname: Baker
authors.forename: S C
authors.initials: SC
authors.lastname: Shewry
authors.forename: T F
authors.initials: TF
authors.lastname: Kagawa
authors.forename: E
authors.initials: E
authors.lastname: Saafi
authors.forename: M L
authors.initials: ML
authors.lastname: Patchett
authors.forename: E N
authors.initials: EN
authors.lastname: Baker
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D011424:Propionibacterium / Q000201:enzymology*; D019998:Racemases and Epimerases / Q000737:chemistry* / Q000235:genetics
chemical_list: D019998:Racemases and Epimerases; C021581:methylmalonyl-coenzyme A racemase