Transcription factor that regulates genes involved in amino acid metabolism. Represses the aspB3 gene, coding for an aspartate transaminase, in the presence of L-aspartate. Another target gene is the basal transcriptional regulator tfbB. Binds also its own promoter. Transcripts accumulate during exponential growth. Is also subject to negative autoregulation. Leads to strong induction of aspB3 and OE_6130F.