"tet(U)" is not a tetracycline resistance determinant

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• The enterococcal plasmid pKQ10 was previously reported to harbor a tetracycline resistance determinant, tet(U).
• The characterization of this determinant has remained incomplete, necessitating further investigation.

Purpose of the Study:

• To rigorously characterize the tet(U) determinant on the enterococcal plasmid pKQ10.
• To determine the functional role of the genetic element designated tet(U) in tetracycline resistance.

Main Methods:

• Experimental studies to assess tetracycline resistance conferred by tet(U).
• Bioinformatic analysis of the genetic sequence associated with tet(U).

Main Results:

• Experimental data failed to substantiate that tet(U) confers resistance to tetracyclines.
• Bioinformatic analysis indicated that the sequence annotated as tet(U) is likely the 3' end of a gene encoding a rolling-circle replication initiator (Rep) protein.

Conclusions:

• The tet(U) determinant on plasmid pKQ10 does not confer tetracycline resistance.
• The genetic element previously identified as tet(U) is likely misannotated and represents a component of a Rep protein gene.