title: Residues in the acetyl CoA binding site of pyruvate carboxylase involved in allosteric regulation.
abstract: We have examined the roles of Asp1018, Glu1027, Arg469 and Asp471 in the allosteric domain of Rhizobium etli pyruvate carboxylase. Arg469 and Asp471 interact directly with the allosteric activator acetyl coenzyme A (acetyl CoA) and the R469S and R469K mutants showed increased enzymic activity in the presence and absence of acetyl CoA, whilst the D471A mutant exhibited no acetyl CoA-activation. E1027A, E1027R and D1018A mutants had increased activity in the absence of acetyl CoA, but not in its presence. These results suggest that most of these residues impose restrictions on the structure and/or dynamics of the enzyme to affect activity.
authors.affiliation: Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand. Electronic address: kamonman.c@hotmail.com.
authors.forename: Kamonman
authors.initials: K
authors.lastname: Choosangtong
authors.affiliation: Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand. Electronic address: yozinomycetes@hotmail.com.
authors.forename: Chaiyos
authors.initials: C
authors.lastname: Sirithanakorn
authors.affiliation: School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia. Electronic address: adinazada@bigpond.com.
authors.forename: Abdul
authors.initials: A
authors.lastname: Adina-Zada
authors.affiliation: School of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, SA 5005, Australia. Electronic address: john.wallace@adelaide.edu.au.
authors.forename: John C
authors.initials: JC
authors.lastname: Wallace
authors.affiliation: Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand. Electronic address: sarawut.jit@mahidol.ac.th.
authors.forename: Sarawut
authors.initials: S
authors.lastname: Jitrapakdee
authors.affiliation: School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia. Electronic address: paul.attwood@uwa.edu.au.
authors.forename: Paul V
authors.initials: PV
authors.lastname: Attwood
mesh_terms: D000105:Acetyl Coenzyme A / Q000737:chemistry / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D000494:Allosteric Regulation; D000495:Allosteric Site; D019943:Amino Acid Substitution; D001120:Arginine / Q000737:chemistry; D001224:Aspartic Acid / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001639:Bicarbonates / Q000737:chemistry; D055162:Biocatalysis; D018698:Glutamic Acid / Q000737:chemistry; D007700:Kinetics; D008274:Magnesium / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D055550:Protein Stability; D011766:Pyruvate Carboxylase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019289:Pyruvic Acid / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D042163:Rhizobium etli / Q000201:enzymology* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D001639:Bicarbonates; D050505:Mutant Proteins; D011994:Recombinant Proteins; D001224:Aspartic Acid; D018698:Glutamic Acid; D000105:Acetyl Coenzyme A; D019289:Pyruvic Acid; D000255:Adenosine Triphosphate; D001120:Arginine; D011766:Pyruvate Carboxylase; D008274:Magnesium
keywords: Acetyl coenzyme A; Allosteric regulation; Pyruvate carboxylase; Rhizobium etli