|
type |
Journal Article |
authors |
Kim, S.S; Yu, Y.G. |
title |
Molecular cloning of an eExtremely thermostable alanine racemase from Aquifex pyrophilus and enzymatic characterization of the expressed protein |
journal |
J Biochem Mol Biol |
Activity |
5.1.1.1 |
Family |
5.1.1.1.a |
sel |
selected |
ui |
NOTinPubmed |
year |
(2000) |
volume |
33 |
number |
\ |
pages |
82-8 |
| |
keywords |
Alanine Racemase/*thermostable |
abstract |
A homologous gene to alanine racemase was cloned from a hyperthermophilic bacterium, Aquifex pyrophilus. The cloned gene encodes a protein of 341 amino acids, which has a significant homology to alanine racemase of Bacillus stearothermophilus, Lactobacillus brevis, and E. coli. When the gene was expressed in Escherichia coli, it produced a 40 kDa protein. The purified protein contains one mole pyridoxal 5-phosphate per one mole of protein, which is essential for catalytic activity of alanine racemase. The purified protein catalyzed racemization of L-alanine to D-alanine, or vice versa, indicating that the cloned gene encoded alanine racemase. It also showed significant racemization activity against L-serine and a-aminobutylic acid. The A. pyrophilus alanine racemase showed strong thermostability, and it maintained catalytic activity in the presence of organic solvents. |
last changed |
2010/06/14 10:48 |
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