Chitinase B of "Microbulbifer degradans" 2-40 contains two catalytic domains with different chitinolytic activities.

ABSTRACT: Chitinase B of "Microbulbifer degradans" 2-40 is a modular protein that is predicted to contain two glycoside hydrolase family 18 (GH18) catalytic domains, two polyserine domains, and an acidic repeat domain. Each of the GH18 domains was shown to be catalytically active against chitin. Activity assays reveal that the amino-terminal catalytic domain (GH18(N)) releases methylumbelliferone from 4'-methylumbelliferyl-N,N'-diacetylchitobiose 13.6-fold faster than the carboxy-terminal catalytic domain (GH18(C)) and releases chitobiose from the nonreducing end of chitooligosaccharides, therefore functioning as an exochitinase. GH18(C) releases methylumbelliferone from 4'-methylumbelliferyl-N,N',N"-triacetylchitotriose 2.7-fold faster than GH18(N) and cleaves chitooligosaccharides at multiple bond

SUBMITTER: Howard MB 

PROVIDER: S-EPMC344425 | biostudies-literature | 2004 Mar

REPOSITORIES: biostudies-literature