A novel thermostable GH5 ß-xylosidase from Thermogemmatispora sp. T81.
N Biotechnol
; 53: 57-64, 2019 Nov 25.
Article
em En
| MEDLINE
| ID: mdl-31299302
A glycoside hydrolase family 5 (GH5) subfamily 22 gene, designated T81Xyl5_22A, was identified in the genome of the aerobic thermophilic bacterium, Thermogemmatispora sp. T81 (locus A4R35_07040). The gene was cloned and heterologously expressed in Escherichia coli and the gene product characterized biochemically. The recombinant enzyme had an optimal catalytic activity at pH5.0 and 65⯰C, and was active against beechwood xylan and rye arabinoxylan. It yielded only xylose molecules as products of beechwood xylan hydrolysis, indicating that it is a GH5 family ß-d-xylosidase. Using 4-nitrophenyl ß-d-xylopyranoside (pNPX) as a substrate, the KM, Vmax, kcat and kcat/KM kinetic parameters were determined as 0.25⯱â¯0.03â¯mM, 889.47⯱â¯28.54â¯U/mg, 39.20â¯s-1 and 156.8â¯mM-1â¯s-1, respectively. Small-angle X-ray scattering (SAXS) data enabled reconstruction of the enzyme's low-resolution molecular envelope and revealed that it formed dimers in solution. As far as we are aware, this is the first description of a thermostable bacterial GH5 family ß-d-xylosidase.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Temperatura
/
Xilosidases
/
Chloroflexi
Idioma:
En
Revista:
N Biotechnol
Assunto da revista:
BIOLOGIA MOLECULAR
/
ENGENHARIA BIOMEDICA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Holanda