Determination of pentapeptide repeat units in Qnr proteins by the structure-based alignment approach.

Title : Determination of pentapeptide repeat units in the Qnr proteins

Structural insights into quinolone antibiotic resistance mediated by pentapeptide repeat proteins: conserved surface loops direct the activity of a Qnr protein from a Gram-negative bacterium

Quinolones inhibit bacterial type II DNA topoisomerases (e.g. DNA gyrase) and are among the most important antibiotics in current use. However, their efficacy is now being threatened by various plasmid-mediated resistance determinants. Of these, the pentapeptide repeat-containing (PRP) Qnr proteins are believed to act as DNA mimics and are particularly prevalent in gram-negative bacteria. Predi...

Qnr-like pentapeptide repeat proteins in gram-positive bacteria.

OBJECTIVES To study the role of Qnr-like pentapeptide repeat proteins (PRPs) from several gram-positive species with quinolone resistance in vitro. METHODS A PCR-based strategy was used to clone and express genes coding for Qnr-like PRPs in Enterococcus faecalis, Enterococcus faecium, Listeria monocytogenes, Clostridium perfringens, C. difficile, Bacillus cereus and B. subtilis in Escherichia...

Designing Of Degenerate Primers-Based Polymerase Chain Reaction (PCR) For Amplification Of WD40 Repeat-Containing Proteins Using Local Allignment Search Method

Degenerate primers-based polymerase chain reaction (PCR) are commonly used for isolation of unidentified gene sequences in related organisms. For designing the degenerate primers, we propose the use of local alignment search method for searching the conserved regions long enough to design an acceptable primer pair. To test this method, a WD40 repeat-containing domain protein from Beauveria bass...

Phylogenetic analysis of chromosomally determined qnr and related proteins.

qnr genes were discovered on plasmids by their ability to reduce quinolone susceptibility, but homologs can be found in the genomes of at least 92 Gram-negative, Gram-positive, and strictly anaerobic bacterial species. The related pentapeptide repeat protein-encoding mfpA gene is present in the genome of at least 19 species of Mycobacterium and 10 other Actinobacteria species. The native functi...