CLONING AND TRANSCRIPTIONAL ANALYSIS OF THE LIPA (LIPOIC ACID SYNTHETASE) GENE FROM RHIZOBIUM-ETLI

We report here the isolation of a Rhizobium etli gene involved in lipo ic acid metabolism, the lipA gene, which complements a lipA mutant str ain of Escherichia coli. A promoter region (lipAp) was mapped immediat ely upstream of lipA and two in vivo transcription initiation sites we re identified, preceded by sequences showing some homology to the -10/ -35 promoter consensus sequences. The activity of the lipAp was found not to be regulated either by the carbon source or by the addition of lipoic acid. Moreover, quantitative analysis of the lipA transcript by RNase protection assays indicated its down-regulation during entry in to stationary phase.