title: A Novel highly thermostable branched-chain amino acid aminotransferase from the crenarchaeon Vulcanisaeta moutnovskia.
abstract: A new fold-type IV branched-chain amino acid aminotransferase VMUT0738 from the hyperthermophilic Crenarchaeon Vulcanisaeta moutnovskia was successfully expressed in Escherichia coli. Purified VMUT0738 showed activity toward numerous aliphatic and aromatic l-amino acids and 2-oxo acids at optimal pH 8.0. Distinguishing features of the VMUT0738 compared with typical BCAT are the absence of activity toward acidic substrates, high activity toward basic ones, and low but detectable activity toward the (R)-enantiomer of α-methylbenzylamine (0.0076U/mg) The activity of VMUT0738 increases with a rise in the temperature from 60°C to 90°C. VMUT0738 showed high thermostability (after 24h incubation at 70°C the enzyme lost only 27% of the initial activity) and the resistance to organic solvents. The sequence alignment revealed two motifs (V/I)xLDxR and PFG(K/H)YL characteristic of BCATs from species of the related genera Vulcanisaeta, Pyrobaculum and Thermoproteus that might be responsible for the unique substrate recognition profile of the enzyme.
authors.affiliation: A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Ave. 33, bld. 2, 119071, Moscow, Russian Federation. Electronic address: tstekh@yandex.ru.
authors.forename: Tatiana N
authors.initials: TN
authors.lastname: Stekhanova
authors.affiliation: Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Ave. 33, bld. 2, 119071 Moscow, Russian Federation.
authors.forename: Andrey L
authors.initials: AL
authors.lastname: Rakitin
authors.affiliation: Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Ave. 33, bld. 2, 119071 Moscow, Russian Federation.
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Mardanov
authors.affiliation: A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Ave. 33, bld. 2, 119071, Moscow, Russian Federation.
authors.forename: Ekaterina Yu
authors.initials: EY
authors.lastname: Bezsudnova
authors.affiliation: A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Ave. 33, bld. 2, 119071, Moscow, Russian Federation; NBICS Center, National Research Centre "Kurchatov Institute", Akad. Kurchatova sqr 1, 123182 Moscow, Russian Federation.
authors.forename: Vladimir O
authors.initials: VO
authors.lastname: Popov
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004795:Enzyme Stability; D019766:Genes, Archaeal; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D040681:Structural Homology, Protein; D013379:Substrate Specificity; D013696:Temperature; D019624:Thermoproteaceae / Q000201:enzymology* / Q000235:genetics; D000637:Transaminases / Q000235:genetics / Q000378:metabolism*
chemical_list: D019843:Archaeal Proteins; D011994:Recombinant Proteins; D000637:Transaminases; C019798:branched-chain-amino-acid transaminase
keywords: Branched-chain amino acid aminotransferase; Sequence motifs; Substrate specificity; Thermostability