A tellurite-resistance genetic determinant from phytopathogenic pseudomonads encodes a thiopurine methyltransferase: evidence of a widely-conserved family of methyltransferases.
A tellurite-resistance genetic determinant was isolated from the pea blight pathogen Pseudomonas syringae pathovar pisi by a shotgun strategy involving a tellurite-selective screening in Escherichia coli. A 1.65 kb tellurite resistance insert was obtained and analysed. It harbours a single complete and functional ORF encoding a deduced protein of 24, 445 Da. The deduced AA sequence shows significant similarities with the complete human thiopurine methyltransferase enzyme, a methyltransferase from Synechocystis and a methyltransferase-like sequence from Bordetella pertussis. The encoded thiopurine methyltransferase activity was demonstrated using a radiochemical microassay for the methylation of 6-mercaptopurine. This gene was detected in most P. syringae legume pathogens.
Cournoyer
B
B
Department of Biological Sciences, University of the West of England, Bristol BS16 1QY, UK. cournoye@biomserv.univ-lyn1.fr
Watanabe
S
S
Vivian
A
A
D000595:Amino Acid Sequence; D001483:Base Sequence; D004352:Drug Resistance, Microbial; D005798:Genes, Bacterial; D008780:Methyltransferases / Q000235:genetics*; D008969:Molecular Sequence Data; D018532:Pisum sativum / Q000382:microbiology*; D011549:Pseudomonas / Q000201:enzymology / Q000235:genetics*; D015183:Restriction Mapping; D016415:Sequence Alignment; D013691:Tellurium / Q000494:pharmacology*
D008780:Methyltransferases; C022745:thiopurine methyltransferase; C026660:tellurous acid; D013691:Tellurium