Enzymatic and genetic characterization of the DasD protein possessing N-acetyl-β-d-glucosaminidase activity in Streptomyces coelicolor A3(2).
نویسندگان
چکیده
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 Streptomyces coelicolor A3(2). To clarify the roles of the DasD protein in the degradation and assimilation of chitin, we obtained and characterized a recombinant DasD protein and a dasD-null mutant of S. coelicolor A3(2). The recombinant DasD protein produced in Escherichia coli showed N-acetyl-β-d-glucosaminidase (GlcNAcase) 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 A3(2). Immuno-blot analysis demonstrated that DasD is a cytoplasmic protein. The dasD-null mutant exhibited cellular GlcNAcase activity which was comparable with that of the parent strain M145. DasD, thus, did not seem to be a major GlcNAcase. Induced extracellular chitinase activity in the dasD-null mutant was, interestingly, higher than M145, in the presence of colloidal chitin or (GlcNAc)(2) . In contrast to M145, (GlcNAc)(2) temporally accumulated in the culture supernatant of the dasD-null mutant in the presence of colloidal chitin.
منابع مشابه
Characterization of a Novel Intracellular Endopeptidase of the / Hydrolase Family from Streptomyces coelicolor A3(2)
In a proteasome-lacking mutant of Streptomyces coelicolor A3(2), an intracellular enzyme with chymotrypsinlike activity, absent from the wild type, was detected. Complementation that restored proteasome function did not suppress expression of the endopeptidase. Since the enzyme was not found in two other S. coelicolor proteasome mutants, its expression probably resulted from a secondary mutatio...
متن کاملPURIFICATION AND PROPERTIES OF RAT GASTROCNEMIUS MUSCLE N-ACETYL-I3-DGLUCOSAMINIDASE A AND B.
N-acetyl-B-D-Glucosaminidase was purified by affinity and ionexchange chromatography. Two major, A and B, and three minor intermediate forms were isolated and characterized. NAG-A and NAG-B were purified 440 and 1200 fold with final yields of 16 and 23 percent respectively. Each activity was represented by a single protein band. After 70 min preincubation at 55°C a loss of70% activity of N...
متن کاملThe genetic location of prophage on the chromosome of Streptomyces coelicolor.
HE genetic structure of Streptomyces coelicolor A3 (2), the only strain among the actinomycetes for which a genetic map has been constructed, was studied in detail by HOPWOOD (1967) and SERMONTI (1 969). For genetic analysis, HOPWOOD and SERMONTI utilized the capacity of mutant strains of A3 (2) to undergo genetic recombination. To enlarge the possibilities of genetic analysis of the actinomyce...
متن کاملIncrease of lead-induced release of N-acetyl-p-D-glucosaminidase by NO synthase in perfused kidney of rat
Urinary N-acetyl-β-D-glucosalninidase (NAG) has been proved to be a useful marker of early renal injury as a result of factors such as lead toxicity. In this study the effect of lead acetate on the kidney and its correlation with the nitric oxide (NO) system was investigated by determining the NAG release in perfused kidney of rat. Lead acetate caused a time- and dose-dependent increase in en...
متن کاملPurification of a malonyltransferase from Streptomyces coelicolor A3(2) and analysis of its genetic determinant.
Streptomyces coelicolor A3(2) synthesizes each half molecule of the dimeric polyketide antibiotic actinorhodin (Act) from one acetyl and seven malonyl building units, catalyzed by the Act polyketide synthase (PKS). The synthesis is analogous to fatty acid biosynthesis, and there is evident structural similarity between PKSs of Streptomyces spp. and fatty acid synthases (FASs). Each system shoul...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- FEMS microbiology letters
دوره 340 1 شماره
صفحات -
تاریخ انتشار 2013