Comparison of SXT and R391, two conjugative integrating elements: definition of a genetic backbone for the mobilization of resistance determinants.
The SXT element (SXT) is becoming an increasingly prevalent vector for the dissemination of antibiotic resistances in Vibrio cholerae. SXT is a member of a larger family of elements, formerly defined as IncJ plasmids, that are self-transmissible by conjugation and integrate site-specifically into the host chromosome. Comparison of the DNA sequences of SXT and R391, an IncJ element from Providencia rettgeri, indicate that these elements consist of a conserved backbone that mediates the regulation, excision/integration and conjugative transfer of the elements. Both elements have insertions into this backbone that either confer the element-specific properties or are of unknown function. Interestingly, the conserved SXT and R391 backbone apparently contains hotspots for insertion of additional DNA sequences. This backbone represents a scaffold for the mobilization of genetic material between a wide range of gram-negative bacteria, allowing for rapid adaptation to changing environments.
Beaber
J W
JW
Division of Geographic Medicine/Infectious Diseases, New England Medical Center, NEMC 041, 750 Washington St., Boston, Massachusetts 02111, USA.
Burrus
V
V
Hochhut
B
B
Waldor
M K
MK
D001483:Base Sequence; D003227:Conjugation, Genetic; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004352:Drug Resistance, Microbial / Q000235:genetics*; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D018626:Retroelements; D016415:Sequence Alignment
D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D018626:Retroelements