Novobiocin binding to NalD induces the expression of the MexAB‐OprM pump in Pseudomonas aeruginosa. Issue 5 (16th March 2016)

• Record Type: Journal Article
• Authors: Chen, Weizhong; Wang, Dan; Zhou, Wenquan; Sang, Hong; Liu, Xichun; Ge, Zhiyun; Zhang, Jin; Lan, Lefu; Yang, Cai‐Guang; Chen, Hao
• Is Part Of: Molecular microbiology. Volume 100:Issue 5(2016)
• Page Start: 749
• Page End: 758
• Publication Date: 2016-03-16
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.13346
• Languages: English
• ISSNs: 0950-382X

Abstract

Summary: NalD was reported to be the secondary repressor of the MexAB‐OprM multidrug efflux pump, the major system contributing to intrinsic multidrug resistance in Pseudomonas aeruginosa . Here, we show that novobiocin binds directly to NalD, which leads NalD to dissociate from the DNA promoter, and thus de‐represses the expression of the MexAB‐OprM pump. In addition, we have solved the crystal structure of NalD at a resolution of 2.90 Å. The structural alignment of NalD to its homologue TtgR reveals that the residues N129 and H167 in NalD are involved in its novobiocin‐binding ability. We have confirmed the function of these two amino acids by EMSA and plate assay. The results presented here highlight the importance and diversity of regulatory mechanism in bacterial antibiotic resistance, and provide further insight for novel antimicrobial development. Abstract : NalD is the secondary repressor of the MexAB‐OprM multidrug efflux pump, the major system contributing to intrinsic multidrug resistance in Pseudomonas aeruginosa . We identify novobiocin as binding directly to NalD, which leads NalD to dissociate from DNA promoter and thus de‐represses the expression of the MexAB‐OprM efflux pump.