Noble, Christian Guy, Vasudevan, Dileep and Rao, Srinivasa P.S. (2013) Structural basis of mycobacterial inhibition by Cyclomarin A. Journal of Biological Chemistry, 288 (43). ISSN 0021-92581083-351X

Abstract

Cyclomarin A (CymA) was identified as a mycobactericidal compound targeting ClpC1. However the target was identified based on pull-down experiments and in vitro binding data, without direct functional evidence in mycobacteria. Here we show that CymA specifically binds to the N-terminal domain of ClpC1. In addition we have determined the co-crystal structure of CymA bound to the N-terminal domain of ClpC1 to high resolution. Based on the structure of the complex several mutations were engineered into ClpC1 which showed reduced CymA binding in vitro. The ClpC1 mutants were overexpressed in mycobacteria and two showed resistance to CymA, providing the first direct evidence that ClpC1 is the target of CymA. Phe80 is important in vitro and in cells for the ClpC1-CymA interaction and this explains why other bacteria are resistant to CymA. A model for how CymA binding to the N-terminal domain of ClpC1 leads to uncontrolled proteolysis by the associated ClpP protease machinery is discussed.

Item Type:	Article
Date Deposited:	26 Apr 2016 23:46
Last Modified:	26 Apr 2016 23:46
URI:	https://oak.novartis.com/id/eprint/9332