As expected for a PhoP-activated gene , there was no slyA transcription when bacteria were grown under PhoP-repress-ing conditions ( i.e. 10 mM Mg2 ) , regardless of the presence of a functional phoP gene ( Fig. 4A ) .
Our results from primer-extension demonstrate that transcriptions of the identified loci are activated by PhoP because the mRNA level of transcripts is reduced significantly in the slyA mutants grown in low-Mg2 conditions -LRB- Fig .