Genetic organization, nucleotide sequence and regulation of expression of genes encoding phenol hydroxylase and catechol 1,2-dioxygenase in Acinetobacter calcoaceticus NCIB8250.

TitleGenetic organization, nucleotide sequence and regulation of expression of genes encoding phenol hydroxylase and catechol 1,2-dioxygenase in Acinetobacter calcoaceticus NCIB8250.
Publication TypeJournal Article
Year of Publication1995
AuthorsEhrt S, Schirmer F, Hillen W
JournalMol Microbiol
Volume18
Issue1
Pagination13-20
Date Published1995 Oct
ISSN0950-382X
KeywordsAcinetobacter calcoaceticus, Amino Acid Sequence, Base Sequence, Catechol 1,2-Dioxygenase, Cloning, Molecular, Dioxygenases, Gene Expression Regulation, Bacterial, Genes, Bacterial, Genetic Complementation Test, Mixed Function Oxygenases, Molecular Sequence Data, Mutation, Operon, Oxygenases, Phenol, Phenols, Recombinant Fusion Proteins, Regulatory Sequences, Nucleic Acid, RNA, Bacterial, RNA, Messenger, Sequence Analysis, DNA, Sequence Homology, Amino Acid, Species Specificity, Transcription, Genetic
Abstract

We have mutated Acinetobacter calcoaceticus NCIB-8250 to growth deficiency on phenol as sole carbon source and isolated genes with similarity to phenol hydroxylase and catechol 1,2-dioxygenase by complementation. Sequence analysis reveals the presence of six open reading frames (ORFs) with similarities to a Pseudomonas multicomponent phenol hydroxylase which are followed by an ORF with similarity to catA from A. calcoaceticus ADP1. Transformation of these genes to ADP1 confers the ability to grow at the expense of phenol as sole carbon source. Primer extension analysis indicates phenol-inducible transcription from an RpoN-dependent promoter sharing sequence similarity with the sigma 54 consensus promoter sequence, except that the -12 box is GG instead of GC. A catA::lacZ transcriptional fusion shows the same induction profile for beta-galactosidase expression as transcription from the sigma 54-dependent promoter. This result suggests that catA is cotranscribed in the same operon with the phenol hydroxylase-encoding genes and is consistent with the fact that no apparent additional promoter is found for catA by sequence analysis or primer extension. Catechol 1,2-dioxygenase activity is induced in NCIB8250 by benzoate, whereas beta-galactosidase expression from the catA::lacZ fusion is not. This observation leads to the hypothesis that two differentially regulated catA genes should be present in that strain.

DOI10.1111/j.1365-2958.1995.mmi_18010013.x
Alternate JournalMol Microbiol
PubMed ID8596453

Weill Cornell Medicine Microbiology and Immunology 1300 York Avenue, Box 62 New York, NY 10065 Phone: (212) 746-6505 Fax: (212) 746-8587