Page WJ, Mehrotra M, Vande Woestyne M, Tindale AE, Kujat Choy SL, Macyk AS, Leskiw BK. Iron-regulated phenylalanyl-tRNA synthetase activity in Azotobacter vinelandii.
FEMS Microbiol Lett 2003;
218:15-21. [PMID:
12583892 DOI:
10.1111/j.1574-6968.2003.tb11492.x]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
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.
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