1998 journal article

Regulation of the transcriptional activators AnfA and VnfA by metals and ammonium in Azotobacter vinelandii

FEMS Microbiology Letters, 164(1), 63–68.

By: R. Premakumar n, R. Pau*, L. Mitchenall *, M. Easo n & P. Bishop n

MeSH headings : Acetates / pharmacology; Azotobacter vinelandii / drug effects; Azotobacter vinelandii / enzymology; Azotobacter vinelandii / genetics; Bacterial Proteins / drug effects; Bacterial Proteins / genetics; Cloning, Molecular; DNA-Binding Proteins / drug effects; DNA-Binding Proteins / genetics; Gene Expression Regulation, Bacterial / genetics; Metals / pharmacology; Molybdenum / pharmacology; Trans-Activators / drug effects; Trans-Activators / genetics; Vanadium / pharmacology; beta-Galactosidase / metabolism
TL;DR: Transcription of the genes encoding molybdenum (Mo)-independent nitrogenases 2 and 3 of Azotobacter vinelandii requires the activators VnfA and AnfA, respectively and Mo-dependent repression of anfA transcription is influenced but not entirely mediated by the Mo-responsive regulator ModE. (via Semantic Scholar)
Source: NC State University Libraries
Added: August 6, 2018

Transcription of the genes encoding molybdenum (Mo)-independent nitrogenases 2 and 3 of Azotobacter vinelandii requires the activators VnfA and AnfA, respectively. The effect of NH4+, Mo, or V (vanadium) was tested on the expression of vnfA-lacZ and anfA-lacZ transcriptional fusions. Mo repressed expression of both fusions whereas NH4+ and V repressed the anfA-lacZ fusion, but not the vnfA-lacZ fusion. Thus the repressive effect on transcription of the anfHDGKOR operon by NH4+, Mo, or V is mediated through their effect on transcription of anfA and the repressive effect of Mo on the vnfHFd and vnfDGK operons is mediated through Mo repression of vnfA transcription. Mo-dependent repression of anfA transcription is influenced but not entirely mediated by the Mo-responsive regulator ModE.