Streptomyces species synthesize more than 70 medically important antibiotics as well as antitumor and antiparasitic agents. These compounds are produced as secondary metabolites during nutritional limitation and the initiation of sporulation. However, the mechanisms which regulate the initiation of secondary metabolism and sporulation in Streptomyces are not understood. The synthesis of both glutamine synthetase (GS), a key enzyme in nitrogen assimilation, and the antibiotic, actinorhodin, are increased during nitrogen limitation in S. coelicolor. Investigations of the regulation of GS in other bacterial systems have identified global regulatory networks which activate gene expression in response to nitrogen availability. The GS gene will be used as a handle for studying regulatory mechanisms responsible for alterations in gene expression during nitrogen limitation in Streptomyces. Two approaches will be used to investigate the regulation of the GS gene in S. coelicolor. First, the S. coelicolor GS structural gene (glnA) which has been cloned in this laboratory will be physically characterized to determine the glnA promoter and coding region. Secondly, factors involved in GS regulation will be identified genetically by the isolation of mutants altered in the ability to synthesize GS. The glnA cloned DNA will then be used to study the interactions between the glnA promoter and the genetically identified GS regulatory proteins, RNA polymerase and small nitrogen-containing compounds. An understanding of the mechanisms which mediate nitrogen regulation of GS in Streptomyces will allow rational strategies to be used for the increased production of antibiotics and other secondary metabolites, and the isolation of novel secondary metabolites. Furthermore, it should be possible to develop a better understanding of the regulatory mechanisms involved in the initiation of secondary metabolism and sporulation in Streptomyces.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI023168-04
Application #
3135067
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1987-12-01
Project End
1989-09-29
Budget Start
1988-07-01
Budget End
1989-09-29
Support Year
4
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Boston University
Department
Type
Schools of Medicine
DUNS #
604483045
City
Boston
State
MA
Country
United States
Zip Code
02118
Wray Jr, L V; Fisher, S H (1994) Analysis of Bacillus subtilis hut operon expression indicates that histidine-dependent induction is mediated primarily by transcriptional antitermination and that amino acid repression is mediated by two mechanisms: regulation of transcription initiation J Bacteriol 176:5466-73
Wray Jr, L V; Atkinson, M R; Fisher, S H (1994) The nitrogen-regulated Bacillus subtilis nrgAB operon encodes a membrane protein and a protein highly similar to the Escherichia coli glnB-encoded PII protein. J Bacteriol 176:108-14
Fisher, S H; Strauch, M A; Atkinson, M R et al. (1994) Modulation of Bacillus subtilis catabolite repression by transition state regulatory protein AbrB. J Bacteriol 176:1903-12
Wray Jr, L V; Pettengill, F K; Fisher, S H (1994) Catabolite repression of the Bacillus subtilis hut operon requires a cis-acting site located downstream of the transcription initiation site. J Bacteriol 176:1894-902
Wray Jr, L V; Fisher, S H (1993) The Streptomyces coelicolor glnR gene encodes a protein similar to other bacterial response regulators. Gene 130:145-50
Atkinson, M R; Wray Jr, L V; Fisher, S H (1993) Activation of the Bacillus subtilis hut operon at the onset of stationary growth phase in nutrient sporulation medium results primarily from the relief of amino acid repression of histidine transport. J Bacteriol 175:4282-9
Fisher, S H; Sonenshein, A L (1991) Control of carbon and nitrogen metabolism in Bacillus subtilis. Annu Rev Microbiol 45:107-35
Wray Jr, L V; Atkinson, M R; Fisher, S H (1991) Identification and cloning of the glnR locus, which is required for transcription of the glnA gene in Streptomyces coelicolor A3(2). J Bacteriol 173:7351-60
Fisher, S H (1989) Glutamate synthesis in Streptomyces coelicolor. J Bacteriol 171:2372-7
Fisher, S H; Wray Jr, L V (1989) Regulation of glutamine synthetase in Streptomyces coelicolor. J Bacteriol 171:2378-83

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