Identification of a novel family of carbohydrate-binding modules with broad ligand specificity.
Sci Rep
; 6: 19392, 2016 Jan 14.
Article
en En
| MEDLINE
| ID: mdl-26765840
ABSTRACT
Most enzymes that act on carbohydrates include non-catalytic carbohydrate-binding modules (CBMs) that recognize and target carbohydrates. CBMs bring their appended catalytic modules into close proximity with the target substrate and increase the hydrolytic rate of enzymes acting on insoluble substrates. We previously identified a novel CBM (CBMC5614-1) at the C-terminus of endoglucanase C5614-1 from an uncultured microorganism present in buffalo rumen. In the present study, that the functional region of CBMC5614-1 involved in ligand binding was localized to 134 amino acids. Two representative homologs of CBMC5614-1, sharing the same ligand binding profile, targeted a range of ß-linked polysaccharides that adopt very different conformations. Targeted substrates included soluble and insoluble cellulose, ß-1,3/1,4-mixed linked glucans, xylan, and mannan. Mutagenesis revealed that three conserved aromatic residues (Trp-380, Tyr-411, and Trp-423) play an important role in ligand recognition and targeting. These results suggest that CBMC5614-1 and its homologs form a novel CBM family (CBM72) with a broad ligand-binding specificity. CBM72 members can provide new insight into CBM-ligand interactions and may have potential in protein engineering and biocatalysis.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Carbohidratos
/
Enzimas
/
Metabolismo de los Hidratos de Carbono
/
Dominios y Motivos de Interacción de Proteínas
Tipo de estudio:
Diagnostic_studies
Idioma:
En
Revista:
Sci Rep
Año:
2016
Tipo del documento:
Article
País de afiliación:
China