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.
Department of Biologic and Materials Sciences, School of Dentistry, The University of Michigan, Ann Arbor, Michigan 48109, USA.
M Victoria
MV
Francia
Don B
DB
Clewell
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