Disease relevance of tetK

• Studies of membrane vesicles from Escherichia coli expressing low levels of complete and 3'-truncated versions of tetA(L) or tetK, now show that the full-length versions of both transporters catalyze electrogenic antiport and that demonstration of electrogenicity depends upon use of a low chloride buffer for the assay [1].
• Expression of the tetK gene from Staphylococcus aureus in Escherichia coli: comparison of substrate specificities of TetA(B), TetA(C), and TetK efflux proteins [2].
• A tet(M) gene that is 100% homologous to the tet(M) gene of Staphylococcus aureus has been found in a clinical isolate of Acinetobacter baumannii, which also carries the tet(A) gene encoding a tetracycline efflux pump [3].

High impact information on tetK

• If an outwardly directed gradient of Na+ or K+ was present, Rb+ uptake occurred without energization in vesicles from cells transformed with a plasmid containing tetA(L) or tetK but not a control plasmid [1].
• In summary, our data indicate that the observed dramatic enhancement by EGCg of tetracycline activity for resistant staphylococcal isolates is caused by impairment of tetracycline efflux pump activity and increased intracellular retention of the drug, suggesting a possible use of EGCg as an adjuvant in antibacterial therapy [4].
• Mutations in the tetA(B) gene that cause a change in substrate specificity of the tetracycline efflux pump [5].
• A double disc diffusion method has been developed to identify inducible resistance to minocycline and to distinguish between tetK, tetM and tetKM isolates [6].
• Allele replacement of the femAB operon with the tetracycline resistance determinant tetK in a methicillin-resistant Staphylococcus aureus strain resulted in impaired growth, methicillin hypersusceptibility, and lysostaphin resistance [7].

Chemical compound and disease context of tetK

• A diverse collection of methicillin-resistant Staphylococcus aureus (MRSA) isolates resistant to tetracycline was screened by PCR for the presence of the resistance determinants tetK, tetL, tetM or tetO [6].

Biological context of tetK

• Some were due to point mutations in the clfB promoter that led to increased expression of the tetK gene [8].
• The array is equipped with oligonucleotide capture probes for the detection of 10 clinically and therapeutically relevant antibiotic resistance genes and -mutations (mecA, aacA-aphD, tetK, tetM, vat(A), vat(B), vat(C), erm(A), erm(C), grlA-mutation) as well as several control probes [9].
• The corrected DNA sequence of the tet(K) structural gene, encoding the tetracycline efflux protein from Staphylococcus aureus, is reported [10].

Associations of tetK with chemical compounds

• The tetK gene, as well as the tetA(B) gene from the transposon Tn10 and the tetA(C) gene from plasmid pBR322, was subjected to the regulatory control of the lac repressor, and resistance to tetracycline was measured as a function of the isopropyl-beta-D-thiogalactopyranoside concentration [2].
• Resistance to tetracycline and doxycycline was greater (two- to four-fold) in tetK cells preincubated with tetracycline (tetK MRSA isolates were susceptible to minocycline </=0.25 mg/L under all conditions tested) [6].

References