Investigation of the cofactor-binding site of Zymomonas mobilis pyruvate decarboxylase by site-directed mutagenesis
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منابع مشابه
Pyruvate decarboxylase from Zymomonas mobilis
To study the mechanism of re-activation of Zymomonas mobilis pyruvate decarboxylase apoenzyme by its cofactors thiamin diphosphate and Mg2", cofactor-free enzyme was prepared by dialysis against I mM-dipicolinic acid at pH 8.2. This apoenzyme was then used in a series of experiments that included determination of: (a) the affinity towards one cofactor when the other was present at saturating co...
متن کاملSite-directed mutagenesis of the ionizable groups in the active site of Zymomonas mobilis pyruvate decarboxylase: effect on activity and pH dependence.
Pyruvate decarboxylase (PDC, EC 4.1.1.1) is a thiamin diphosphate-dependent enzyme about which there is a large body of structural and functional information. The active site contains several absolutely conserved ionizable groups and all of these appear to be important, as judged by the fact that mutation diminishes or abolishes catalytic activity. Previously we have shown [Schenk, G., Leeper, ...
متن کاملActive site mutants of pyruvate decarboxylase from Zymomonas mobilis--a site-directed mutagenesis study of L112, I472, I476, E473, and N482.
The homotetrameric pyruvate decarboxylase (PDC) from Zymomonas mobilis requires the cofactors thiamin diphosphate and Mg2+ for catalytic activity. We have investigated the role of various amino acid residues in the direct environment of the active site. The role of residue E473 in the catalytic activity and stability of the enzyme was probed by several mutations. All mutant enzymes were either ...
متن کاملNucleotide sequence of the pyruvate decarboxylase gene from Zymomonas mobilis.
Pyruvate decarboxylase (EC 4.1.1.1), the penultimate enzyme in the alcoholic fermentation pathway of Zymomonas mobilis, converts pyruvate to acetaldehyde and carbon dioxide. The complete nucleotide sequence of the structural gene encoding pyruvate decarboxylase from Zymomonas mobilis has been determined. The coding region is 1704 nucleotides long and encodes a polypeptide of 567 amino acids wit...
متن کاملExchanging the substrate specificities of pyruvate decarboxylase from Zymomonas mobilis and benzoylformate decarboxylase from Pseudomonas putida.
Pyruvate decarboxylase from Zymomonas mobilis (PDC) and benzoylformate decarboxylase from Pseudomonas putida (BFD) are thiamine diphosphate-dependent enzymes that decarboxylate 2-keto acids. Although they share a common homotetrameric structure they have relatively low sequence similarity and different substrate spectra. PDC prefers short aliphatic substrates whereas BFD favours aromatic 2-keto...
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ژورنال
عنوان ژورنال: Biochemical Journal
سال: 1994
ISSN: 0264-6021,1470-8728
DOI: 10.1042/bj3000007