Characterization of Acetohydroxyacid Synthase Cofactors from Haemophilus influenza
نویسندگان
چکیده
منابع مشابه
Characterization of acetohydroxyacid synthase from the hyperthermophilic bacterium Thermotoga maritima
Acetohydroxyacid synthase (AHAS) is the key enzyme in branched chain amino acid biosynthesis pathway. The enzyme activity and properties of a highly thermostable AHAS from the hyperthermophilic bacterium Thermotoga maritima is being reported. The catalytic and regulatory subunits of AHAS from T. maritima were over-expressed in Escherichia coli. The recombinant subunits were purified using a sim...
متن کاملExpression, purification and characterization of Arabidopsis thaliana acetohydroxyacid synthase.
Acetohydroxyacid synthase (EC 4.1.3.18) is the enzyme that catalyses the first step in the synthesis of the branched-chain amino acids valine, leucine and isoleucine. The AHAS gene from Arabidopsis thaliana with part of the chloroplast transit sequence removed was cloned into the bacterial expression vector pT7-7 and expressed in the Escherichia coli strain BL21(DE3). The expressed enzyme was p...
متن کاملMolecular evolution of acetohydroxyacid synthase in bacteria
Acetohydroxyacid synthase (AHAS) is the key enzyme in the biosynthetic pathways of branched chain amino acids in bacteria. Since it does not exist in animal and plant cells, AHAS is an attractive target for developing antimicrobials and herbicides. In some bacteria, there is a single copy of AHAS, while in others there are multiple copies. Therefore, it is necessary to investigate the origin an...
متن کاملSuicide inhibition of acetohydroxyacid synthase by hydroxypyruvate.
Acetohydroxyacid synthase (Ec 2.2.1.6) catalyses the thiamine diphosphate-dependent reaction between two molecules of pyruvate yielding 2-acetolactacte and CO2. The enzyme will also utilise hydroxypyruvate with a k(cat) value that is 12% of that observed with pyruvate. When hydroxypyruvate is the substrate, the enzyme undergoes progressive inactivation with kinetics that are characteristic of s...
متن کاملMutagenesis of Escherichia coli acetohydroxyacid synthase isoenzyme II and characterization of three herbicide-insensitive forms.
Sulphonylurea and imidazolinone herbicides act by inhibiting acetohydroxyacid synthase (AHAS; EC 4.1.3.18), the enzyme that catalyses the first step in the biosynthesis of branched-chain amino acids. AHAS requires as cofactors thiamin diphosphate, a bivalent metal ion and, usually, FAD. Escherichia coli contains three isoenzymes and this study concerns isoenzyme II, the most herbicide-sensitive...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Bulletin of the Korean Chemical Society
سال: 2010
ISSN: 0253-2964
DOI: 10.5012/bkcs.2010.31.12.3782