@article{mbs:/content/journal/micro/10.1099/00221287-147-8-2157, author = "Providenti, Miguel A and Mampel, Jörg and MacSween, Scott and Cook, Alasdair M and Wyndham, R. Campbell", title = "Comamonas testosteroni BR6020 possesses a single genetic locus for extradiol cleavage of protocatechuateThe GenBank accession number for the sequence reported in this paper is AF305325.", journal= "Microbiology", year = "2001", volume = "147", number = "8", pages = "2157-2167", doi = "https://doi.org/10.1099/00221287-147-8-2157", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-147-8-2157", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "meta ring fission", keywords = "Pca, protocatechuate", keywords = "biodegradation", keywords = "Cm, chloramphenicol", keywords = "PDCH, 2-pyrone-4,6-dicarboxylic acid hydrolase", keywords = "HCMSD, HCMS dehydrogenase", keywords = "aromatic", keywords = "HCMS, 2-hydroxy-4-carboxymuconate semialdehyde", keywords = "lig genes", keywords = "OCA, 4-oxalocitramalate aldolase", keywords = "Ap, ampicillin", keywords = "PMD, Pca 4,5-dioxygenase", keywords = "MMA, minimal medium A", keywords = "Km, kanamycin", abstract = "A key intermediate for biodegradation of various distinct aromatic growth substrates in Comamonas testosteroni is protocatechuate (Pca), which is metabolized by the 4,5-extradiol (meta) ring fission pathway. A locus harbouring genes from C. testosteroni BR6020 was cloned, dubbed pmd, which encodes the enzymes that degrade Pca. The identity of pmdAB, encoding respectively the α- and β-subunit of the Pca ring-cleavage enzyme, was confirmed by N-terminal sequencing and molecular mass determination of both subunits from the separated enzyme. Disruption of pmdA resulted in a strain unable to grow on Pca and a variety of aromatic substrates funnelled through this compound (m- and p-hydroxybenzoate, p-sulfobenzoate, phthalate, isophthalate, terephthalate, vanillate, isovanillate and veratrate). Growth on benzoate and o-aminobenzoate (anthranilate) was not affected in this strain, indicating that these substrates are metabolized via a different lower pathway. Tentative functions for the products of other pmd genes were assigned based on sequence identity and/or similarity to proteins from other proteobacteria involved in uptake or metabolism of aromatic compounds. This study provides evidence for a single lower pathway in C. testosteroni for metabolism of Pca, which is generated by different upper pathways acting on a variety of aromatic substrates.", }