Biomaterial Database

Isolation of a chitinase overproducing mutant of Streptomyces peucetius defective in daunorubicin biosynthesis. 2000

K S Vetrivel, and K Dharmalingam

Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, India.

Streptomyces peucetius, producer of the antitumor anthracycline antibiotic daunorubicin, was mutagenized, and mutants defective in daunorubicin biosynthesis were screened. One mutant (SPVI), which failed to produce daunorubicin, was found to overproduce an extracellular chitinase. Time course analyses of chitinase production and of the extracellular protein profile showed that the increase in activity is due to increased synthesis of the enzyme protein. The production of chitinase in SPVI was repressed by glucose as in the case of wild-type S. peucetius. PFGE analysis of VspI restriction fragments of S. peucetius and SPVI showed that there was no major alteration in the mutant genome. The hybridization pattern of S. peucetius and SPVI genomic DNA digested with various restriction enzymes was identical when probed with dnrUVJI genes of the S. peucetius daunorubicin cluster and chiA of Streptomyces lividans 66. The possible step affected in the daunorubicin biosynthetic pathway could be a polyketide synthase, since aklanonic acid, the earliest detectable intermediate in the daunorubicin pathway, was not synthesized in SPVI.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D002688	Chitinases	Glycoside hydrolases that break down glycosidic bonds in CHITIN. They are important for insect and worm morphogenesis and plant defense against pathogens. Human chitinases may play a role in the etiology of allergies and asthma.	Chitinase,Endochitinase
D003470	Culture Media	Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.	Media, Culture
D003630	Daunorubicin	A very toxic anthracycline aminoglycoside antineoplastic isolated from Streptomyces peucetius and others, used in treatment of LEUKEMIA and other NEOPLASMS.	Daunomycin,Rubidomycin,Rubomycin,Cerubidine,Dauno-Rubidomycine,Daunoblastin,Daunoblastine,Daunorubicin Hydrochloride,NSC-82151,Dauno Rubidomycine,Hydrochloride, Daunorubicin,NSC 82151,NSC82151
D000903	Antibiotics, Antineoplastic	Chemical substances, produced by microorganisms, inhibiting or preventing the proliferation of neoplasms.	Antineoplastic Antibiotics,Cytotoxic Antibiotics,Antibiotics, Cytotoxic
D013302	Streptomyces	A genus of bacteria that form a nonfragmented aerial mycelium. Many species have been identified with some being pathogenic. This genus is responsible for producing a majority of the ANTI-BACTERIAL AGENTS of practical value.