Mutational Analysis of Quinolone Resistance Protein QnrB1
نویسندگان
چکیده
منابع مشابه
Mutational analysis of quinolone resistance protein QnrB1.
Alanine substitutions and selected deletions have been used to localize amino acids in QnrB essential for its protective activity. Essential amino acids are found at positions i and i(-2) in the pentapeptide repeat module and in the larger of two loops, where deletion of only a single amino acid compromises activity. Deletion of 10 amino acids at the N terminus is tolerated, but removal of 3 am...
متن کاملMutational Analysis of Quinolone Resistance Protein QnrVC7 Provides Novel Insights into the Structure-Activity Relationship of Qnr Proteins.
This study assessed the functional importance of residues located at the i(-2) position of face 4 of the tandem repeat loops of the quinolone resistance protein QnrVC7 through mutagenesis studies. The i(-2) position of face 4 on different coils required residues with different natures. Some substitutions reduced the protective activity of QnrVC7, while some of them increased it. These findings ...
متن کاملMutational analysis of quinolone resistance in the plasmid-encoded pentapeptide repeat proteins QnrA, QnrB and QnrS.
OBJECTIVES Pentapeptide repeat proteins (PRPs) QnrA, QnrB and QnrS confer reduced susceptibility to quinolones. This study presents an in vitro analysis of the genetic evolution of quinolone resistance mediated by changes in the coding sequences and promoter regions of qnrA1, qnrS1 and qnrB1 genes. METHODS A random mutagenesis technique was used to predict the evolutionary potential of these ...
متن کاملPresence of quinolone resistance to qnrB1 genes and blaOXA-48 carbapenemase in clinical isolates of Klebsiella pneumoniae in Spain.
A study is presented on the presence of quinolone resistance qnrB1 genes in clinical isolates belonging to the largest series of infections caused by OXA-48-producing Klebsiella pneumoniae in a single-centre outbreak in Spain. Evidence is also provided, according to in vitro results, that there is a possibility of co-transfer of plasmid harbouring blaOXA-48 with an other plasmid harbouring qnrB...
متن کاملQuinolone resistance mutations in the GrlB protein of Staphylococcus aureus.
Two altered GrlB proteins (one with an Asp-432-->Asn alteration and one with an Asn-470-->Asp alteration) of Staphylococcus aureus were purified as fusion proteins to maltose-binding protein. The 50% inhibitory concentrations of levofloxacin were 14 and 3.4 microg/ml against topoisomerase IV containing GrlB proteins with alterations at positions 432 and 470, respectively. These results suggest ...
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ژورنال
عنوان ژورنال: Antimicrobial Agents and Chemotherapy
سال: 2013
ISSN: 0066-4804,1098-6596
DOI: 10.1128/aac.01533-13