prkA genomic context and expression analysis. (a) R. etli prkA is the first gene of a three-gene operon. Open reading frames are represented by right facing arrows, genomic coordinates are indicated above. Restriction sites for the deletion insertion of the prkA mutant are depicted by downwards facing triangles, and primer sites for RT-PCR used to determine prkA operon structure are depicted by left and right facing triangles. (b) Expression of prkA-gusA transcriptional reporter fusion was monitored in different R. etli mutant backgrounds during growth in AMS succinate. The strains were the wild type R. etli CFN42, rsh mutant, prkA mutant, ntrC mutant and rpoN1 mutant. Expression levels are shown in Miller units and are the means of three biological replicates with error bars representing the standard deviation. Exp., exponential; Stat., stationary.