ISSN:
1574-6968
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Azotobacter vinelandii strain UA22 was produced by pTn5luxAB mutagenesis, such that the promoterless luxAB genes were transcribed in an iron-repressible manner. Tn5luxAB was localized to a fragment of chromosomal DNA encoding the thrS, infC, rpmI, rplT, pheS and pheT genes, with Tn5 inserted in the 3′-end of pheS. The isolation of this mutation in an essential gene was possible because of polyploidy in Azotobacter, such that strain UA22 carried both wild-type and mutant alleles of pheS. Phenylalanyl-tRNA synthetase activity and pheS::luxAB reporter activity was partially repressed under iron-sufficient conditions and fully derepressed under iron-limited conditions. The ferric uptake regulator (Fur) bound to a DNA sequence immediately upstream of luxAB, within the pheS gene, but pheS::luxAB reporter activity was not affected by phenylalanine availability. This suggests there is novel regulation of pheST in A. vinelandii by iron availability.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1574-6968.2003.tb11492.x
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