Disease relevance of mppA

• An E. coli strain whose entire opp operon was deleted but which carried the mppA locus was unable to grow on murein tripeptide unless it was provided with oppBCDF genes in trans [1].

High impact information on mppA

• Overproduction of MppA repressed marA transcription in TP985 but not in other mppA or marR mutants [2].
• Reduced production of OmpF similar to that observed in the multiple antibiotic resistance phenotype is also seen in the mppA mutant [3].
• Normal sensitivity of the mppA mutant to these agents is restored by mppA expressed from a plasmid [3].
• We have found serendipitously that E. coli K-12 strains carrying a null mutation in mppA exhibit increased resistance to a wide spectrum of antibiotics and to cyclohexane [3].
• Overproduction of cytoplasmic GadA and GadB and of several unidentified cytoplasmic membrane proteins as well as reduction in the amount of the outer membrane protein, OmpP, in the mppA null mutant indicate that MppA regulates a number of genes in addition to those already known to be controlled by MarA [3].

Biological context of mppA

• A plasmid carrying the wild-type mppA gene allows the mutant to grow on tripeptide [1].

References