The Synechococcus strain PCC 7942 glnN product (glutamine synthetase III) helps recovery from prolonged nitrogen chlorosis

J Bacteriol. 2000 Oct;182(19):5615-9. doi: 10.1128/JB.182.19.5615-5619.2000.


We report the cloning and sequencing of the glnN gene encoding a class III glutamine synthetase from the cyanobacterium Synechococcus strain PCC 7942. Mapping of the transcriptional start site revealed a DNA sequence in the promoter region that resembles an imperfect NtcA binding motif. Expression of glnN is impaired in NtcA- and P(II)-deficient mutants. The only parameter which was negatively affected in the glnN mutant compared to the wild type was the recovery rate of prolonged nitrogen-starved cells with low concentrations of combined nitrogen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Base Sequence
  • Cyanobacteria / enzymology*
  • Cyanobacteria / genetics
  • DNA, Bacterial
  • DNA-Binding Proteins / genetics
  • Gene Expression Regulation, Bacterial
  • Glutamate-Ammonia Ligase / genetics
  • Glutamate-Ammonia Ligase / metabolism*
  • Molecular Sequence Data
  • Mutagenesis
  • Nitrogen / metabolism*
  • PII Nitrogen Regulatory Proteins
  • Time Factors
  • Transcription Factors / genetics


  • Bacterial Proteins
  • DNA, Bacterial
  • DNA-Binding Proteins
  • PII Nitrogen Regulatory Proteins
  • Transcription Factors
  • ntcA protein, Synechococcus
  • PIID regulatory protein, Bacteria
  • Glutamate-Ammonia Ligase
  • Nitrogen

Associated data

  • GENBANK/AF251806