Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1993 Apr;175(7):2037-45.
doi: 10.1128/jb.175.7.2037-2045.1993.

Analysis of the promoter and regulatory sequences of an oxygen-regulated bch operon in Rhodobacter capsulatus by site-directed mutagenesis

D Ma  1 , D N Cook, D A O'Brien, J E Hearst
Affiliations

Analysis of the promoter and regulatory sequences of an oxygen-regulated bch operon in Rhodobacter capsulatus by site-directed mutagenesis

D Ma et al. J Bacteriol. 1993 Apr.

Abstract

The biosynthesis of pigments (carotenoids and bacteriochlorophylls) in the photosynthetic bacterium Rhodobacter capsulatus is regulated by the oxygen concentration in the environment. However, the mechanism of this regulation has remained obscure. In this study, transcriptional fusions of the bchCXYZ promoter region to lacZ were used to identify the promoter and regulatory sequences governing transcription of these bacteriochlorophyll biosynthesis genes. The promoter region was identified in vivo by making deletions and site-directed mutations. The 50 bp upstream of the promoter region was shown to be required for the oxygen-dependent transcriptional regulation of bchCXYZ. A previously described palindrome sequence is also likely involved in the regulation. A gel mobility shift assay further defined the interaction of transcription regulators with these DNA sequence elements in vitro and demonstrated that a DNA-protein complex is formed at this promoter region. Since the suggested promoter sequence and the palindrome sequence are found upstream of several other bch and crt operons, these sequences may be responsible for regulating oxygen-dependent pigment biosynthesis at the level of transcription in R. capsulatus. In addition, these cis-acting DNA elements are not found upstream of puh and puf operons, which encode the structural polypeptides of the reaction center and light-harvesting I complexes. This observation supports the model of different regulatory mechanism for the pigment biosynthesis enzymes and structural polypeptides required for the production of the photosynthetic apparatus.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Arch Microbiol. 1975 Nov 7;105(3):207-16 - PubMed
    1. Cell. 1992 Mar 6;68(5):945-54 - PubMed
    1. J Bacteriol. 1981 Jun;146(3):1003-12 - PubMed
    1. Methods Enzymol. 1983;100:293-308 - PubMed
    1. J Bacteriol. 1984 Mar;157(3):945-8 - PubMed

Publication types

MeSH terms