Open AccessTranscription of the glnB and glnA genes in the photosynthetic bacterium Rhodospirillum rubrum
Author(s) -
Magnus Johansson,
Stefan Nordlund
Publication year - 1996
Publication title -
microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 179
eISSN - 1465-2080
pISSN - 1350-0872
DOI - 10.1099/13500872-142-5-1265
Subject(s) - rhodospirillum rubrum , gene , biology , promoter , glutamine synthetase , transcription (linguistics) , nucleic acid sequence , genetics , microbiology and biotechnology , bacteria , biochemistry , amino acid , gene expression , glutamine , linguistics , philosophy
The PII protein, encoded by glnB, has a central role in the control of nitrogen metabolism in nitrogen-fixing prokaryotes. The glnB gene of Rhodospirillum rubrum was isolated and sequenced. The deduced amino acid sequence had very high sequence identity to other PII proteins. The glnA gene, encoding glutamine synthetase, was located 135 bp downstream of glnB and was partially sequenced. glnB is cotranscribed with glnA from a promoter with high similarity to the sigma 54-dependent promoter consensus sequence. A putative sigma 70 promoter was also identified further upstream of glnB. Northern blotting analyses showed that in addition glnA is either transcribed from an unidentified promoter or, more likely, that the glnBA transcript is processed to give the glnA mRNA. The total level of the two transcripts was much higher in nitrogen-fixing cells than in ammonia-grown cells.