Serratia marcescens chitinase A and B (ChiA and ChiB)

Serratia marcescens chitinases A and B are major enzymes involved in the breakdown of chitin, an insoluble polysaccharide found in fungal cell walls and arthropod exoskeletons. Chitinase A (ChiA) and chitinase B (ChiB) are glycosyl hydrolases from family 18, each with a distinct domain architecture. ChiB features a catalytic TIM-barrel domain and a chitin-binding domain; its action as an exochitinase allows stepwise breakdown from the nonreducing end, while ChiA complements this activity, resulting in synergistic chitin degradation[1][4]. Both chitinases are crucial components of the chitinolytic machinery secreted by S. marcescens, a Gram-negative bacterium renowned as a model system for polysaccharide conversion and as an opportunistic pathogen in humans. Chitinases have significant potential as biotechnological tools in agriculture (i.e., as antifungal agents and biopesticides) but are not currently direct targets for approved drugs.

Other names

Chitinase A (ChiA)Chitinase B (ChiB)S. marcescens chitinase AS. marcescens chitinase B

Hydrolysis of chitin polysaccharides by cleaving β-1,4 glycosidic bonds. ChiB: exochitinase mechanism degrading chitin from the non-reducing end. ChiA: acts synergistically with ChiB for efficient chitin breakdown