A novel thermostable GH5 beta-xylosidase from Thermogemmatispora sp. T81

Autor(es)

Tomazini, Atilio ^[1] ; Higasi, Paula ^[1] ; Manzine, Livia R. ^[1] ; Stott, Matthew ^[2] ; Sparling, Richard ^[3] ; Levin, David B. ^[4] ; Polikarpov, Igor ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Inst Phys, Sao Carlos, SP - Brazil

^[2] Univ Canterbury, Sch Biol Sci, Christchurch - New Zealand

^[3] Univ Manitoba, Dept Microbiol, Winnipeg, MB - Canada

^[4] Univ Manitoba, Dept Biosyst Engn, Winnipeg, MB - Canada

• Tipo de documento: Artigo Científico
• Fonte: NEW BIOTECHNOLOGY; v. 53, p. 57-64, NOV 25 2019.
• Citações Web of Science: 0

Resumo

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 degrees 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 beta-D-xylosidase. Using 4-nitrophenyl beta-D-xylopyranoside (pNPX) as a substrate, the K-M, Vmax, k(cat) and k(cat)/K-M kinetic parameters were determined as 0.25 +/- 0.03 mM, 889.47 +/- 28.54 U/mg, 39.20 s(-1) and 156.8 mM(-1) 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 beta-D-xylosidase. (AU)

• Processo FAPESP: 15/13684-0 - Estudos estruturais e funcionais de enzimas que participam na síntese e degradação de carboidratos complexos
• Beneficiário: Igor Polikarpov
• Modalidade de apoio: Auxílio à Pesquisa - Temático