Relationship between hemagglutinin and sialidase from Clostridium perfringens CN3870: gel filtration of mutant and reverant activities

N-acetylglucosamine recognition by a family 32 carbohydrate-binding module from Clostridium perfringens NagH

Many carbohydrate-active enzymes have complex architectures comprising multiple modules that may be involved in catalysis, carbohydrate binding, or protein-protein interactions. Carbohydrate-binding modules (CBMs) are a common ancillary module whose function is to promote the adherence of the complete enzyme to carbohydrate substrates. CBM family 32 has been proposed to be one of the most diverse CBM families classified to date, yet all of the structurally characterized CBM32s thus far recognize galactose-based ligands. Here, we report a unique binding specificity and mode of ligand binding for a family 32 CBM. NagHCBM32-2 is one of four CBM32 modules in NagH, a family 84 glycoside hydrolase secreted by Clostridium perfringens. NagHCBM32-2 has the beta-sandwich scaffold common to members of the family; however, its specificity for N-acetylglucosamine is unusual among CBMs. X-ray crystallographic analysis of the module at resolutions from 1.45 to 2.0 A and in complex with disaccharides reveals that its mode of sugar recognition is quite different from that observed for galactose-specific CBM32s. This study continues to unravel the diversity of CBMs found in family 32 and how these CBMs might impart the carbohydrate-binding specificity to the extracellular glycoside hydrolases in C. perfringens.

Molecular genetics and pathogenesis of Clostridium perfringens

Clostridium perfringens is the causative agent of a number of human diseases, such as gas gangrene and food poisoning, and many diseases of animals. Recently significant advances have been made in the development of C. perfringens genetics. Studies on bacteriocin plasmids and conjugative R plasmids have led to the cloning and analysis of many C. perfringens genes and the construction of shuttle plasmids. The relationship of antibiotic resistance genes to similar genes from other bacteria has been elucidated. A detailed physical map of the C. perfringens chromosome has been prepared, and numerous genes have been located on that map. Reproducible transformation methods for the introduction of plasmids into C. perfringens have been developed, and several genes coding for the production of extracellular toxins and enzymes have been cloned. Now that it is possible to freely move genetic information back and forth between C. perfringens and Escherichia coli, it will be possible to apply modern molecular methods to studies on the pathogenesis of C. perfringens infections.

Relationship between hemagglutinin and sialidase from Clostridium perfringens CN3870: chromatographic characterization of the biologically active proteins

Biochemical characterization of hemagglutinin and sialidase activities from Clostridium perfringens strain CN3870 revealed that this strain produced three sialidase enzymes that were separable to gel filtration, ion exchange chromatography, and polyacrylamide gel electrophoresis. The molecular weights of sialidase I, II, and III activities were 310,000 +/- 10,000, 105,000 +/- 4,000 and 64,000 +/- 2,000, respectively, the first figure being an approximate value only.