Open AccessIdentification of genes associated with copper tolerance in an adhesion‐defective mutant of Aeromonas veronii biovar sobria
Author(s) -
Francki Kathy T,
Chang Barbara J,
Mee Brian J,
Collig Peter J,
Susai Veronica,
Keese Paul K
Publication year - 2000
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2000.tb01513.x
Subject(s) - biology , orfs , aeromonas , mutant , microbiology and biotechnology , aeromonas veronii , genbank , pseudomonas syringae , open reading frame , gene , genetics , nucleic acid sequence , peptide sequence , sequence analysis , bacteria
Tn phoA mutagenesis was used to identify adhesins of Aeromonas veronii biovar sobria 3767, a strain isolated from a diarrhoeal stool specimen. Six mutants, from a library of 154, exhibited significantly reduced levels of adhesion to HEp‐2 cells. Primers to the terminal regions of Tn phoA were used for inverse PCR and the product from one mutant was cloned into pBluescript and partial sequence data obtained. Scanning GenBank and EMBL data bases revealed DNA sequence similarity to the cop A gene of Pseudomonas syringae pv. tomato which confers resistance to copper and other heavy metals. The transposon was located within the cop A gene and the mutant exhibited a reduced tolerance to copper. Primer walking, using the inverse PCR product as a template, revealed three open reading frames (ORFs) cop A, B and C in A. veronii biovar sobria 3767. The predicted amino acid sequences of ORFs A and B had significant homology (55 and 34% respectively) to the cop A and B proteins of P. syringae . No amino acid or DNA sequence homology existed between ORF C of strain 3767 and any other gene in the data bases scanned. Further analysis of the nucleotide sequence failed to reveal the presence of typical copper regulatory genes within the vicinity of the Aeromonas sequence. The association between copper tolerance and adhesion in A. veronii biovar sobria requires further study.