Molecular insights into substrate specificity and thermal stability of a bacterial GH5-CBM27 endo-1,4-beta-D-mannanase

Autor(es)

dos Santos, Camila Ramos ^[1] ; Paiva, Joice Helena ^[1] ; Meza, Andreia Navarro ^[1] ; Cota, Junio ^[2] ; Alvarez, Thabata Maria ^[2] ; Ruller, Roberto ^[2] ; Prade, Rolf Alexander ^[3] ; Squina, Fabio Marcio ^[2] ; Murakami, Mario Tyago ^[1]

Afiliação do(s) autor(es)

^[1] Ctr Nacl Pesquisa Energia & Mat, Lab Nacl Biociencias LNBio, BR-13083970 Campinas, SP - Brazil

^[2] Ctr Nacl Pesquisa Energia & Mat, Lab Nacl Ciencia & Tecnol Bioetanol CTBE, BR-13083970 Campinas, SP - Brazil

^[3] Oklahoma State Univ, Dept Microbiol & Mol Genet, Stillwater, OK 74078 - USA

• Tipo de documento: Artigo Científico
• Fonte: Journal of Structural Biology; v. 177, n. 2, p. 469-476, FEB 2012.
• Citações Web of Science: 18

Resumo

The breakdown of beta-1,4-mannoside linkages in a variety of mannan-containing polysaccharides is of great importance in industrial processes such as kraft pulp delignification, food processing and production of second-generation biofuels, which puts a premium on studies regarding the prospection and engineering of beta-mannanases. In this work, a two-domain beta-mannanase from Thermotoga petrophila that encompasses a GH5 catalytic domain with a C-terminal CBM27 accessory domain, was functionally and structurally characterized. Kinetic and thermal denaturation experiments showed that the CBM27 domain provided thermo-protection to the catalytic domain, while no contribution on enzymatic activity was observed. The structure of the catalytic domain determined by SIRAS revealed a canonical (alpha/beta)(8)-barrel scaffold surrounded by loops and short helices that form the catalytic interface. Several structurally related ligand molecules interacting with TpMan were solved at high-resolution and resulted in a wide-range representation of the subsites forming the active-site cleft with residues W134, E198, R200, E235, H283 and W284 directly involved in glucose binding. (C) 2011 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 10/51890-8 - SMolBNet 2.0: estudos estruturais de fatores de transcrição reguladores dos genes de enzimas hidrolíticas e de swollenin em Aspergillus niger e A. fumigatus
• Beneficiário: Mário Tyago Murakami
• Modalidade de apoio: Auxílio à Pesquisa - Regular