Light-induced carotenogenesis in Streptomyces coelicolor A3(2): identification of an extracytoplasmic function sigma factor that directs photodependent transcription of the carotenoid biosynthesis gene cluster.
Carotenoids are produced by a variety of organisms, but the mechanisms that regulate gene expression leading to carotenoid biosynthesis have been characterized for only a few organisms. In this study, we found that Streptomyces coelicolor A3(2), a gram-positive filamentous bacterium, produces carotenoids under blue light induction. The carotenoid fraction isolated from the cell extract contained multiple compounds, including isorenieratene and beta-carotene. The carotenoid biosynthesis gene cluster of S. coelicolor consists of two convergent operons, crtEIBV and crtYTU, as previously shown for Streptomyces griseus. The crtEIBV null mutant completely lost its ability to produce carotenoids. The crt gene cluster is flanked by a regulatory region that consists of two divergent operons, litRQ and litSAB. The lit (light-induced transcription) genes encode a MerR-type transcriptional regulator (LitR), a possible oxidoreductase (LitQ), an extracytoplasmic function sigma factor (sigmaLitS), a putative lipoprotein (LitA), and a putative anti-sigma factor (LitB). S1 protection assay revealed that the promoters preceding crtE (PcrtE), crtY (PcrtY), litR (PlitR), and litS (PlitS) are activated upon illumination. A litS mutant lost both the ability to produce carotenoids and the activities of PcrtE, PcrtY, and PlitS, which suggested that sigmaLitS directs light-induced transcription from these promoters. An RNA polymerase holocomplex containing purified sigmaLitS recombinant protein generated specific PcrtE and PcrtY transcripts in an in vitro runoff transcriptional assay. A litR mutant that had an insertion of the kanamycin resistance gene was defective both in the ability to produce carotenoids and in all of the light-dependent promoter activities. Overexpression of litS resulted in constitutive carotenoid production in both the wild type and the litR mutant. These results indicate that sigmaLitS acts as a light-induced sigma factor that directs transcription of the crt biosynthesis gene cluster, whose activity is controlled by an unknown LitR function. This is the first report to describe light-inducible gene expression in Streptomyces.
Takano
Hideaki
H
Life Science Research Center, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa 252-8510, Japan.
Obitsu
Saemi
S
Beppu
Teruhiko
T
Ueda
Kenji
K
D000595:Amino Acid Sequence; D001483:Base Sequence; D002338:Carotenoids / Q000096:biosynthesis*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D008027:Light; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000502:physiology; D011401:Promoter Regions, Genetic; D012808:Sigma Factor / Q000378:metabolism*; D048372:Streptomyces coelicolor / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000502:physiology*
D012808:Sigma Factor; D002338:Carotenoids
Proc Natl Acad Sci U S A. 2003 Feb 18;100(4):1541-6
12563033
Mol Microbiol. 2003 Jan;47(2):561-71
12519205
Mol Microbiol. 2003 Apr;48(1):237-51
12657058
Nat Biotechnol. 2003 May;21(5):526-31
12692562
FEMS Microbiol Rev. 2003 Jun;27(2-3):145-63
12829265
Gene. 2003 Nov 27;320:127-35
14597396
J Bacteriol. 1966 Feb;91(2):535-45
5935340
Arch Biochem Biophys. 1967 Jul;121(1):35-49
6035068
Gene. 1982 Oct;19(3):327-36
6295884
J Gen Microbiol. 1983 Sep;129(9):2703-14
6313861
Gene. 1985;33(1):103-19
2985470
J Bacteriol. 1989 Dec;171(12):6710-9
2512283
J Biol Chem. 1990 May 15;265(14):8329-38
2159477
Proc Natl Acad Sci U S A. 1990 Dec;87(24):9975-9
2263648
Mol Gen Genet. 1995 May 10;247(3):387-90
7770044
Eur J Biochem. 1995 Oct 1;233(1):238-48
7588751
FASEB J. 1996 Feb;10(2):228-37
8641556
Mol Gen Genet. 1996 Oct 28;252(6):658-66
8917308
Biochim Biophys Acta. 1999 Jul 9;1439(1):57-64
10395965
Microbiology. 1999 Sep;145 ( Pt 9):2265-71
10517579
J Mol Microbiol Biotechnol. 2001 Jan;3(1):95-101
11200234
Mol Microbiol. 2001 May;40(4):804-14
11401688
Mol Microbiol. 2001 Nov;42(3):809-19
11722744
J Biol Chem. 2002 Mar 1;277(9):7262-70
11748235
Nature. 2002 May 9;417(6885):141-7
12000953
Gene. 2003 Mar 13;306:79-89
12657469