Impact of cellulose properties on enzymatic degradation by bacterial GH48 enzymes: Structural and mechanistic insights from processive Bacillus licheniformis Cel48B cellulase

Author(s)

Araujo, Evandro A. ; Dias, Artur Hermano Sampaio ; Kadowaki, Marco A. S. ; Piyadov, Vasily ; Pellegrini, Vanessa O. A. ; Urio, Mateus B. ; Ramos, Luiz P. ; Skaf, Munir S. ; Polikarpov, Igor

• Document type: Journal article
• Source: Carbohydrate Polymers; v. 264, p. 13-pg., 2021-04-12.

Abstract

Processive cellulases are highly efficient molecular engines involved in the cellulose breakdown process. However, the mechanism that processive bacterial enzymes utilize to recruit and retain cellulose strands in the catalytic site remains poorly understood. Here, integrated enzymatic assays, protein crystallography and computational approaches were combined to study the enzymatic properties of the processive BlCel48B cellulase from Bacillus licheniformis. Hydrolytic efficiency, substrate binding affinity, cleavage patterns, and the apparent processivity of bacterial BlCel48B are significantly impacted by the cellulose size and its surface morphology. BlCel48B crystallographic structure was solved with ligands spanning -5 to -2 and +1 to +2 subsites. Statistical coupling analysis and molecular dynamics show that co-evolved residues on active site are critical for stabilizing ligands in the catalytic tunnel. Our results provide mechanistic insights into BlCel48B molecular-level determinants of activity, substrate binding, and processivity on insoluble cellulose, thus shedding light on structure-activity correlations of GH48 family members in general. (AU)

• FAPESP's process: 14/00769-5 - Structural studies of glycoside hydrolyses in solution using small-angle scattering (SAS) techniques
• Grantee: Vasilii Piiadov
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 13/08293-7 - CCES - Center for Computational Engineering and Sciences
• Grantee: Munir Salomao Skaf
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 15/13684-0 - Structural and functional studies of enzymes that participate in complex carbohydrates synthesis and degradation
• Grantee: Igor Polikarpov
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/17350-0 - Molecular modeling of carbohydrate-modifying enzymes
• Grantee: Artur Hermano Sampaio Dias
• Support Opportunities: Scholarships in Brazil - Doctorate