Insights into the genetic organization of the Corynebacterium diphtheriae erythromycin resistance plasmid pNG2 deduced from its complete nucleotide sequence.
The complete nucleotide sequence of the erythromycin resistance plasmid pNG2 from the human pathogen Corynebacterium diphtheriae S601 was determined. The plasmid has a total size of 15,100 bp and contains at least 17 coding regions. Comparative genomics identified conserved motifs within replication initiator proteins of corynebacterial plasmids and a novel nucleotide sequence feature, termed 22-bp box, located downstream of the repA gene. The erythromycin resistance determinant erm(X) is flanked by inverted repeats of the novel insertion sequence IS3504, which may be responsible for a spontaneous deletion of the antibiotic resistance gene region. Furthermore, pNG2 encodes a putative conjugative relaxase, a membrane protein of the natural resistance-associated macrophage protein (Nramp) family and a protein with Nudix hydrolase signature. Expression of the predicted coding regions of pNG2 in Escherichia coli JM109 was demonstrated by reverse transcription-polymerase chain reaction (RT-PCR) assays. The detailed annotation of the entire pNG2 sequence provided genetic information regarding its molecular evolution and its role in dissemination of antibiotic resistance genes by horizontal gene transfer.
Tauch
Andreas
A
Zentrum für Genomforschung, Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany. andreas.tauch@genetik.uni-bielfeld.de
Bischoff
Nicole
N
Brune
Iris
I
Kalinowski
Jörn
J
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D017124:Conserved Sequence; D003353:Corynebacterium diphtheriae / Q000187:drug effects / Q000235:genetics*; D004265:DNA Helicases / Q000235:genetics; D004254:DNA Nucleotidyltransferases / Q000235:genetics; D004251:DNA Transposable Elements; D021901:DNA, Intergenic; D004268:DNA-Binding Proteins; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004917:Erythromycin / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics; D023061:Gene Order; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics*; D011506:Proteins / Q000235:genetics; D011755:Pyrophosphatases / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators; D000096964:Nudix Hydrolases
D001426:Bacterial Proteins; D004265:DNA Helicases; D004254:DNA Nucleotidyltransferases; D004251:DNA Transposable Elements; D021901:DNA, Intergenic; D004268:DNA-Binding Proteins; D004917:Erythromycin; D011506:Proteins; D011755:Pyrophosphatases; D015534:Trans-Activators; C045264:replication initiator protein; C110340:DNA relaxase; C422942:nudix hydrolase Orf135; D000096964:Nudix Hydrolases