TY - JOUR
T1 - Transcriptional regulatory cascade of nitrogen‐fixation genes in anoxygenic photosynthetic bacteria
T2 - oxygen‐and nitrogen‐responsive factors
AU - Kranz, R. G.
AU - Foster‐Hartnett, D.
PY - 1990/11
Y1 - 1990/11
N2 - Many photosynthetic bacteria from aquatic and terrestrial habitats reduce atmospheric dinitrogen to ammonia. The synthesis of proteins required for nitrogen fixation in these microorganisms is repressed by fixed nitrogen or oxygen. Studies on the purple non‐sulphur phototroph Rhodobacter capsulatus have helped to clarify this transcriptional control and to define the factors involved in this regulation. The molecular mechanisms by which the nitrogen and oxygen status of the cell are relayed into nif gene expression or repression involve many trans‐ and cis‐ acting factors. The roles of these factors in the nif regulatory cascade of R. capsulatus are summarized. Two levels of control are present. The first level of control involves the nitrogen sensing circuitry in which at least four proteins act in a cascade. Upon nitrogen deficiency, genes involved in the second level of control are transcriptionalty activated. These genes encode regulatory proteins that subsequently activate transcription of all other nif genes under anaerobic conditions. The R. capsulatus cascade is compared to the nif regulatory cascade in Klebsiella pneumoniae, highlighting both common and unique aspects.
AB - Many photosynthetic bacteria from aquatic and terrestrial habitats reduce atmospheric dinitrogen to ammonia. The synthesis of proteins required for nitrogen fixation in these microorganisms is repressed by fixed nitrogen or oxygen. Studies on the purple non‐sulphur phototroph Rhodobacter capsulatus have helped to clarify this transcriptional control and to define the factors involved in this regulation. The molecular mechanisms by which the nitrogen and oxygen status of the cell are relayed into nif gene expression or repression involve many trans‐ and cis‐ acting factors. The roles of these factors in the nif regulatory cascade of R. capsulatus are summarized. Two levels of control are present. The first level of control involves the nitrogen sensing circuitry in which at least four proteins act in a cascade. Upon nitrogen deficiency, genes involved in the second level of control are transcriptionalty activated. These genes encode regulatory proteins that subsequently activate transcription of all other nif genes under anaerobic conditions. The R. capsulatus cascade is compared to the nif regulatory cascade in Klebsiella pneumoniae, highlighting both common and unique aspects.
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U2 - 10.1111/j.1365-2958.1990.tb02027.x
DO - 10.1111/j.1365-2958.1990.tb02027.x
M3 - Article
C2 - 2082142
AN - SCOPUS:0025084037
SN - 0950-382X
VL - 4
SP - 1793
EP - 1800
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 11
ER -