This family contains proteins that are similar to the product of the paaX gene of Escherichia coli (Swiss:P76086). This protein is involved in the regulation of expression of a group of proteins known to participate in the metabolism of phenylacetic acid [1].

1: Transcriptional regulation of the divergent paa catabolic operons for phenylacetic acid degradation in Escherichia coli. Ferrandez A, Garcia JL, Diaz E; J Biol Chem 2000;275:12214-12222. PMID:10766858