Adenine deaminase activity of the yicP gene product of Escherichia coli.
Biosci Biotechnol Biochem
; 65(5): 1112-8, 2001 May.
Article
en En
| MEDLINE
| ID: mdl-11440125
ABSTRACT
During previous work on deriving inosine-producing mutants of Escherichia coli, we observed that an excess of adenine added to the culture medium was quickly converted to hypoxanthine. This phenomenon was still apparent after disruption of the known adenosine deaminase gene (add) on the E. coli chromosome, suggesting that, like Bacillus subtilis, E. coli has an adenine deaminase. As the yicP gene of E. coli shares about 35% identity with the B. subtilis adenine deaminase gene (ade), we cloned yicP from the E. coli genome and developed a strain that overexpressed its product. The enzyme was purified from a cell extract of E. coli harboring a plasmid containing the cloned yicP gene, and had significant adenine deaminase [EC 3.5.4.2] activity. It was deduced to be a homodimer, each subunit having a molecular mass of 60 kDa. The enzyme required manganese ions as a cofactor, and adenine was its only substrate. Its optimum pH was 6.5-7.0 and its optimum temperature was 60 degrees C. The apparent Km for adenine was 0.8 mM.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Escherichia coli
/
Genes Bacterianos
/
Aminohidrolasas
Idioma:
En
Revista:
Biosci Biotechnol Biochem
Asunto de la revista:
BIOQUIMICA
/
BIOTECNOLOGIA
Año:
2001
Tipo del documento:
Article
País de afiliación:
Japón