Journal article

Publication year: 1995

Pages: 4481-4487

Journal: Journal of Bacteriology

Volume number: 177

Issue number: 15

ISSN: 0021-9193

DOI Link: https://doi.org/10.1128/jb.177.15.4481-4487.1995

Publisher: American Society for Microbiology

Abstract: 
A 6.4-kb region of a 6.8-kb BamHI fragment carrying Rhodobacter capsulatus genes involved in late steps of cobalamin synthesis has been sequenced. The nucleotide sequence and genetic analysis revealed that this fragment contains eight genes arranged in at least three operons. Five of these eight genes show homology to genes involved in the cobalamin synthesis of Pseudomonas dentrificans and Salmonella typhimurium. The arrangement of these homologous genes differs considerably in the three genera. Upstream of five overlapping genes (named bluFEDCB), a promoter activity could be detected by using lacZ fusions. This promoter shows no regulation by oxygen, vitamin B-12 (cobalamin), or cobinamide. Disruption of the bluE gene by a Tn5 insertion (strain AH2) results in reduced expression of the puf and puc operons, which encode pigment-binding proteins of the photosynthetic apparatus. The mutant strain AH2 can be corrected to a wild-type-like phenotype by addition of vitamin B-12 or cobinamide dicyanide. Disruption of the bluB gene by an interposon (strain BB1) also disturbs the formation of the photosynthetic apparatus. The mutation of strain BB1 can be corrected by vitamin B-12 but not by cobinamide. We propose that a lack of cobalamin results in deregulation and a decreased formation of the photosynthetic apparatus.

Harvard Citation style: Pollich, M. and Klug, G. (1995) Identification and sequence analysis of genes involved in late steps in cobalamin (vitamin B12) synthesis in Rhodobacter capsulatus, Journal of Bacteriology, 177(15), pp. 4481-4487. https://doi.org/10.1128/jb.177.15.4481-4487.1995

APA Citation style: Pollich, M., & Klug, G. (1995). Identification and sequence analysis of genes involved in late steps in cobalamin (vitamin B12) synthesis in Rhodobacter capsulatus. Journal of Bacteriology. 177(15), 4481-4487. https://doi.org/10.1128/jb.177.15.4481-4487.1995