The Streptomyces coelicolor A3(2) lipAR operon encodes an extracellular lipase and a new type of transcriptional regulator.
A region of the Streptomyces coelicolor A3(2) chromosome was identified and cloned by using as a probe the lipase gene from Streptomyces exfoliatus M11. The cloned region consisted of 6286 bp, and carried a complete lipase gene, lipA, as well as a gene encoding a transcriptional activator (lipR). The S. coelicolor A3(2) lipA gene encodes a functional extracellular lipase 82% identical to the S. exfoliatus M11 lipase; the partially purified S. coelicolor enzyme showed a preference for substrates of short to medium chain length. Transcription of lipA was completely dependent on the presence of lipR, and occurred from a single promoter similar to the lipA promoters of S. exfoliatus M11 and Streptomyces albus G. These three Streptomyces lipA promoters have well-conserved -10 and -35 regions, as well as additional conserved sequences upstream of the -35 region, which could function as targets for transcriptional activation by the cognate LipR regulators. The Streptomyces LipR activators are related to other bacterial regulators of a similar size, constituting a previously unidentified family of proteins that includes MalT, AcoK, AlkS, AfsR, five mycobacterial proteins of unknown function and some Streptomyces regulators in antibiotic synthesis clusters. A lipase-deficient strain of S. coelicolor was constructed and found to be slightly affected in production of the polyketide antibiotic actinorhodin.
Valdez
Fabiola
F
Departamento de Biologı́a Molecular, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, 04510 DF, Mexico1.
González-Cerón
Gabriela
G
Departamento de Biologı́a Molecular, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, 04510 DF, Mexico1.
Kieser
Helen M
HM
John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK2.
Servı N-González
Luis
L
Departamento de Biologı́a Molecular, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, 04510 DF, Mexico1.
D000880:Anthraquinones / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000378:metabolism; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D015964:Gene Expression Regulation, Bacterial; D008049:Lipase / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009876:Operon / Q000235:genetics*; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics*; D013379:Substrate Specificity; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D000095622:Benzoisochromanequinones
D000880:Anthraquinones; D000900:Anti-Bacterial Agents; D008049:Lipase; D015719:Single-Strand Specific DNA and RNA Endonucleases; D015534:Trans-Activators; C013390:actinorhodin; D000095622:Benzoisochromanequinones