Amplification of the tetracycline resistance determinant of pAMalpha1 in Enterococcus faecalis requires a site-specific recombination event involving relaxase.
The small multicopy plasmid pAMalpha1 (9.75 kb) encoding tetracycline resistance in Enterococcus faecalis is known to generate tandem repeats of a 4.1-kb segment carrying tet(L) when cells are grown extensively in the presence of tetracycline. Here we show that the initial (rate-limiting) step involves a site-specific recombination event involving plasmid-encoded relaxase activity acting at two recombination sequences (RS1 and RS2) that flank the tet determinant. We also present the complete nucleotide sequence of pAMalpha1.
Francia
M Victoria
MV
Department of Biologic and Materials Sciences, School of Dentistry, The University of Michigan, Ann Arbor, Michigan 48109, USA.
Clewell
Don B
DB
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D003227:Conjugation, Genetic; D013293:Enterococcus faecalis / Q000187:drug effects / Q000235:genetics*; D005784:Gene Amplification; D017353:Gene Deletion; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010957:Plasmids / Q000235:genetics*; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D013752:Tetracycline / Q000494:pharmacology; D013753:Tetracycline Resistance / Q000235:genetics*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C083180:Mob protein, Bacteria; C099206:MobB protein, bacteria; C048817:RepB protein, Bacteria; D015534:Trans-Activators; D013752:Tetracycline