Cloning and sequencing of the cellobiose 2-epimerase gene from an obligatory anaerobe, Ruminococcus albus.
Biochem Biophys Res Commun
; 360(3): 640-5, 2007 Aug 31.
Article
em En
| MEDLINE
| ID: mdl-17612504
ABSTRACT
Cellobiose 2-epimerase (EC 5.1.3.11) was first identified in 1967 as an extracellular enzyme that catalyzes the reversible epimerization between cellobiose and 4-O-beta-D-glucopyranosyl-D-mannose in a culture broth of Ruminococcus albus 7 (ATCC 27210(T)). Here, for the first time, we describe the purification of cellobiose 2-epimerase from R. albus NE1. The enzyme was found to 2-epimerize the reducing terminal glucose moieties of cellotriose and cellotetraose in addition to cellobiose. The gene encoding cellobiose 2-epimerase comprises 1170 bp (389 amino acids) and is present as a single copy in the genome. The deduced amino acid sequence of the mature enzyme contains the possible catalytic residues Arg52, His243, Glu246, and His374. Sequence analysis shows the gene shares a very low level of homology with N-acetyl-D-glucosamine 2-epimerases (EC 5.1.3.8), but no significant homology to any other epimerases reported to date.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Carboidratos Epimerases
/
Celobiose
/
Ruminococcus
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article