RamB is an activator of the pyruvate dehydrogenase complex subunit E1p gene in Corynebacterium glutamicum.

In Corynebacterium glutamicum, the transcriptional regulator RamB negatively controls the expression of genes involved in acetate metabolism. Here we show that during growth in media containing glucose and in complex medium without glucose RamB activates expression of the aceE gene, encoding the E1p subunit of the pyruvate dehydrogenase complex. Thus, RamB functions both as repressor and as activator in C. glutamicum.