Characterization of a novel mutation in the overlap of tlyA and ppnK involved in capreomycin resistance in Mycobacterium.

Abstract

Capreomycin (CAP) is an important second-line drug for multidrug-resistant tuberculosis. To further define the drug resistance mechanism of CAP, a Mycobacterium smegmatis transposon mutant library was constructed using Tn5 transposon for screening isolates with enhanced CAP resistance. A mutant (named C4) with fourfold increased CAP resistance was isolated and characterized. Tn5 was found to be inserted into MSMEG_0841, an annotated pseudogene. However, knockout demonstrated that MSMEG_0841 was not responsible for CAP resistance. We further sequenced the whole genome of C4 and found an A to G substitution in the overlap region between tlyA and ppnK, which leads a stop codon mutation in upstream tlyA and a T2A mutation in downstream ppnK. Mutation in the overlap might confer the dysfuction of both genes. tlyA is a known gene involved in CAP action. Overexpression of ppnK in both Escherichia coli and M. smegmatis confer subtle susceptible to CAP. Taken together, our study found that a novel mutation involved in CAP resistance.

• Authors: Qinglin Du, Quanxin Long, Jinxiao Mao, Tiwei Fu, Xiangke Duan, Jianping Xie
• Journal: IUBMB life (IUBMB Life) Vol. 66 Issue 6 Pg. 405-14 (Jun 2014) ISSN: 1521-6551 [Electronic] England
• PMID: 24890219 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2014 International Union of Biochemistry and Molecular Biology.

Chemical References

• Bacterial Proteins
• Oligonucleotides
• TlyA protein, Mycobacterium tuberculosis
• Capreomycin

Topics

• Bacterial Proteins (genetics)
• Base Sequence
• Capreomycin
• Drug Resistance, Bacterial (genetics)
• Gene Knockout Techniques
• Genome, Bacterial (genetics)
• Microscopy, Electron, Scanning
• Molecular Sequence Data
• Mutation, Missense (genetics)
• Mycobacterium (genetics)
• Oligonucleotides (genetics)
• Real-Time Polymerase Chain Reaction
• Reverse Transcriptase Polymerase Chain Reaction
• Sequence Analysis, DNA