This enzyme is proposed to act in the ring-opening step of phenylacetic acid degradation which follows ligation of the acid with coenzyme A (by PaaF) and hydroxylation by a multicomponent non-heme iron hydroxylase complex (PaaGHIJK). Gene symbols have been standardized in. This enzyme is related to aldehyde dehydrogenases and has a domain which is a member of the pfam00171 family. This family includes sequences from Burkholderia, Bordetella, Streptomyces. Other PaaN enzymes are represented by a separate model, TIGR02278.