Expression, purification and subunit-binding properties of cohesins 2 and 3 of theClostridium thermocellumcellulosome

摘要: The enzymatic subunits of the cellulosome Clostridium thermocellum are integrated into complex by a major non-catalytic polypeptide, called scaffoldin. Its numerous functional domains include single cellulose-binding domain (CBD) and nine subunit-binding domains, or cohesin domains. Two together with adjacent CBD, have been cloned expressed in Escherichia coli, recombinant constructs were purified affinity chromatography on cellulosic matrix. Both which differ about 30% their primary structure, showed similar binding profile to cellulosomal subunits. Calcium ions enhanced dramatically this binding. Under conditions assay, only one catalytic subunit failed bind either domain. results indicate lack selectivity also suggest that additional mechanisms may be involved assembly.