title: Crystallization of the bifunctional methylenetetrahydrofolate dehydrogenase/methenyltetrahydrofolate cyclohydrolase domain of the human trifunctional enzyme.
abstract: Methylenetetrahydrofolate([H4] folate) dehydrogenase (D) and methenyl[H4] folate cyclohydrolase (C) coexist as a bifunctional enzyme (DC) or as the amino-terminal domain of a trifunctional enzyme (DCS) where the third activity is 10-formyl[H4]folate synthetase (S). Two crystal forms of the DC domain of the human cytosolic DCS enzyme have been grown from polyethyleneglycol solution. The monoclinic P2(1) crystals diffract to 2.8 A with a = 72.5 A, b = 68.5 A, c = 125.2 A, and beta = 91.8 degrees but were found to be twinned. The orthorhombic P2(1)2(1)2(1) crystals diffract to 2.5 A with a = 67.7 A, b = 135.9 A, c = 61.6 A, and contain two molecules per asymmetric unit.
authors.affiliation: Institut de Recherche en Biotechnologie, Conseil National de Recherche du Canada, Montréal, Québec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Allaire
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: N R
authors.initials: NR
authors.lastname: Mejia
authors.forename: J N
authors.initials: JN
authors.lastname: Pelletier
authors.forename: R E
authors.initials: RE
authors.lastname: MacKenzie
authors.forename: M
authors.initials: M
authors.lastname: Cygler
mesh_terms: D000619:Aminohydrolases / Q000737:chemistry*; D001665:Binding Sites; D003460:Crystallization; D006801:Humans; D045064:Methenyltetrahydrofolate Cyclohydrolase; D008754:Methylenetetrahydrofolate Dehydrogenase (NADP) / Q000737:chemistry*
chemical_list: D008754:Methylenetetrahydrofolate Dehydrogenase (NADP); D000619:Aminohydrolases; D045064:Methenyltetrahydrofolate Cyclohydrolase