Conversion of Thermobifida fusca free exoglucanases into cellulosomal components: Comparative impact on cellulose-degrading activity

摘要: Cellulosomes are multi-enzyme complexes produced by certain anaerobic bacteria that exhibit efficient degradation of plant cell wall polysaccharides. To understand their enhanced levels hydrolysis, we investigating the effects converting a free-cellulase system into cellulosomal one. achieve this end, replacing cellulose-binding module native cellulases, aerobic bacterium Thermobifida fusca, with cellulosome-derived dockerin established specificity, to allow incorporation defined “designer cellulosomes”. In communication, have attached divergent dockerins two exoglucanases T. fusca exoglucanase, Cel6B and Cel48A. The resultant fusion proteins were shown bind efficiently specifically matching cohesins, activities on several different cellulose substrates compared. lack in had deleterious effect its activity crystalline substrates. contrast, dockerin-bearing family-48 exoglucanase showed increased hydrolytic carboxymethyl both tested, compared wild-type enzyme. marked difference response cellulosome, suggests cellulase is more appropriate than family-6 enzyme as designer cellulosome component.