Mutations inducing an active-site aperture in Rhizobium sp. sucrose isomerase confer hydrolytic activity.
Acta Crystallogr D Biol Crystallogr
; 69(Pt 2): 298-307, 2013 Feb.
Article
en En
| MEDLINE
| ID: mdl-23385465
ABSTRACT
Sucrose isomerase is an enzyme that catalyzes the production of sucrose isomers of high biotechnological and pharmaceutical interest. Owing to the complexity of the chemical synthesis of these isomers, isomaltulose and trehalulose, enzymatic conversion remains the preferred method for obtaining these products. Depending on the microbial source, the ratio of the sucrose-isomer products varies significantly. In studies aimed at understanding and explaining the underlying molecular mechanisms of these reactions, mutations obtained using a random-mutagenesis approach displayed a major hydrolytic activity. Two of these variants, R284C and F164L, of sucrose isomerase from Rhizobium sp. were therefore crystallized and their crystal structures were determined. The three-dimensional structures of these mutants allowed the identification of the molecular determinants that favour hydrolytic activity compared with transferase activity. Substantial conformational changes resulting in an active-site opening were observed, as were changes in the pattern of water molecules bordering the active-site region.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Rhizobium
/
Proteínas Bacterianas
/
Dominio Catalítico
/
Glucosiltransferasas
/
Mutación
Tipo de estudio:
Clinical_trials
Idioma:
En
Revista:
Acta Crystallogr D Biol Crystallogr
Año:
2013
Tipo del documento:
Article
País de afiliación:
Francia