title: Lysine 190 is the catalytic base in MenF, the menaquinone-specific isochorismate synthase from Escherichia coli: implications for an enzyme family.
abstract: Menaquinone biosynthesis is initiated by the conversion of chorismate to isochorismate, a reaction that is catalyzed by the menaquinone-specific isochorismate synthase, MenF. The catalytic mechanism of MenF has been probed using a combination of structural and biochemical studies, including the 2.5 A structure of the enzyme, and Lys190 has been identified as the base that activates water for nucleophilic attack at the chorismate C2 carbon. MenF is a member of a larger family of Mg2+ dependent chorismate binding enzymes catalyzing distinct chorismate transformations. The studies reported here extend the mechanism recently proposed for this enzyme family by He et al.: He, Z., Stigers Lavoie, K. D., Bartlett, P. A., and Toney, M. D. (2004) J. Am. Chem. Soc. 126, 2378-85.
authors.affiliation: Department of Pharmacological Sciences and Center for Structural Biology, Stony Brook University, Stony Brook, New York 11794-5115, USA.
authors.forename: Subramaniapillai
authors.initials: S
authors.lastname: Kolappan
authors.forename: Jacque
authors.initials: J
authors.lastname: Zwahlen
authors.forename: Rong
authors.initials: R
authors.lastname: Zhou
authors.forename: James J
authors.initials: JJ
authors.lastname: Truglio
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Tonge
authors.forename: Caroline
authors.initials: C
authors.lastname: Kisker
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D020134:Catalytic Domain; D002827:Chorismic Acid / Q000378:metabolism; D018360:Crystallography, X-Ray; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D019751:Intramolecular Transferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008239:Lysine / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D024482:Vitamin K 2 / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D011994:Recombinant Proteins; D024482:Vitamin K 2; D019751:Intramolecular Transferases; C058486:isochorismate synthase; D002827:Chorismic Acid; D008239:Lysine