Open AccessEnzymatic and genetic characterization of the D as D protein possessing N ‐acetyl‐β‐ d ‐glucosaminidase activity in S treptomyces coelicolor A 3(2)
Author(s) -
Saito Akihiro,
Ebise Hiroki,
Orihara Yukari,
Murakami Satoshi,
Sano Yukari,
Kimura Akane,
Sugiyama Yuuta,
Ando Akikazu,
Fujii Takeshi,
Miyashita Kiyotaka
Publication year - 2013
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12069
Subject(s) - streptomyces coelicolor , chitin , mutant , biochemistry , escherichia coli , chemistry , microbiology and biotechnology , biology , gene , chitosan
The dasD gene is located just downstream of the dasABC gene cluster, encoding components of an ABC transporter for uptake of a chitin‐degradation product N,N′ ‐diacetylchitobiose [(GlcNAc) 2 ] in S treptomyces coelicolor A 3(2). To clarify the roles of the DasD protein in the degradation and assimilation of chitin, we obtained and characterized a recombinant D as D protein and a dasD ‐null mutant of S . coelicolor A 3(2). The recombinant D as D protein produced in E scherichia coli showed N ‐acetyl‐β‐ d ‐glucosaminidase ( G lc NA case) activity and its optimum temperature and pH were 40 °C and 7, respectively. dasD transcription was strongly induced in the presence of chitin, weakly by chitosan, but not by cellulose or xylan in S . coelicolor A 3(2). Immuno‐blot analysis demonstrated that D as D is a cytoplasmic protein. The dasD ‐null mutant exhibited cellular G lc NA case activity which was comparable with that of the parent strain M145. D as D , thus, did not seem to be a major G lc NA case. Induced extracellular chitinase activity in the dasD ‐null mutant was, interestingly, higher than M 145, in the presence of colloidal chitin or ( G lc NA c) 2 . In contrast to M 145, ( G lc NA c) 2 temporally accumulated in the culture supernatant of the dasD ‐null mutant in the presence of colloidal chitin.