Characterization of a Hexameric Exo-Acting GH51 l-Arabinofuranosidase from the Mesophilic Bacillus subtilis

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• 作者：Zaira B. Hoffmam (1) (2)
  Leandro C. Oliveira (1) (3)
  Junio Cota (1) (2)
  Thabata M. Alvarez (1) (2)
  JosA. Diogo (1) (2)
  Mario de Oliveira Neto (4)
  Ana Paula S. Citadini (1)
  Vitor B. P. Leite (3)
  Fabio M. Squina (1) (2)
  Mario T. Murakami (2) (5)
  Roberto Ruller (1) (2)
  
• 关键词：Arabinofuranosidase ; Glycosyl hydrolase family 51 ; Bacillus subtilis ; Quaternary structure
• 刊名：Molecular Biotechnology
• 出版年：2013
• 出版时间：November 2013
• 年：2013
• 卷：55
• 期：3
• 页码：260-267
• 全文大小：
• 作者单位：Zaira B. Hoffmam (1) (2)
  Leandro C. Oliveira (1) (3)
  Junio Cota (1) (2)
  Thabata M. Alvarez (1) (2)
  JosA. Diogo (1) (2)
  Mario de Oliveira Neto (4)
  Ana Paula S. Citadini (1)
  Vitor B. P. Leite (3)
  Fabio M. Squina (1) (2)
  Mario T. Murakami (2) (5)
  Roberto Ruller (1) (2)
  
  1. Laboratio Nacional de Cicia e Tecnologia do Bioetanol, Centro Nacional de Pesquisa em Energia e Materiais, Rua Giuseppe Maximo Scolfaro 10000, Campinas, SP, 13083-970, Brazil
  2. Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
  3. Departamento de Fica, Instituto de Biocicias, Letras e Cicias Exatas, Universidade Estadual Paulista (IBILCE/UNESP), So Josdo Rio Preto, SP, Brazil
  4. Departamento de Fica e Biofica, Instituto de Biocicias da UNESP de Botucatu, Botucatu, SP, Brazil
  5. Laboratio Nacional de Biocicias (LNBio/CNPEM), Campinas, SP, Brazil
  
• ISSN：1559-0305

文摘

l-Arabinofuranosidases (l-Abfases, EC 3.2.1.55) display a broad specificity against distinct glycosyl moieties in branched hemicellulose and recent studies have demonstrated their synergistic use with cellulases and xylanases for biotechnological processes involving plant biomass degradation. In this study, we examined the structural organization of the arabinofuranosidase (GH51 family) from the mesophilic Bacillus subtilis (AbfA) and its implications on function and stability. The recombinant AbfA showed to be active over a broad temperature range with the maximum activity between 35 and 50, which is desirable for industrial applications. Functional studies demonstrated that AbfA preferentially cleaves debranched or linear arabinan and is an exo-acting enzyme producing arabinose from arabinoheptaose. The enzyme has a canonical circular dichroism spectrum of proteins and exhibits a hexameric quaternary structure in solution, as expected for GH51 members. Thermal denaturation experiments indicated a melting temperature of 53.5, which is in agreement with the temperaturectivity curves. The mechanisms associated with the unfolding process were investigated through molecular dynamics simulations evidencing an important contribution of the quaternary arrangement in the stabilization of the sandwich accessory domain and other regions involved in the formation of the catalytic interface of hexameric Abfases belonging to GH51 family.