Molecular Insights on exquisitely Selective SrtA inhibitors towards active site loop forming open/close lid conformations in SrtA from Bacillus anthracis

The present study clearly explains the dependency of inhibitory activities in SrtA inhibitors is closely related to protein conformational changes of SrtA from Bacillus anthracis B. anthracis Sortase A (SrtA) protein anchors proteins by recognizing a cell wall sorting signal containing the amino acid sequence LPXTG In order to analyze conformational changes and the role of SrtA enzyme, especially the loop motions which situated proximal to the active site molecular dynamic simulation was carried out for 100ns. Particular loop is examined for its various conformations from the MD trajectories and the open/close lid conformations are considered for the enzyme activity validations. Experimentally verified SrtA inhibitors activity was analyzed through 3D-QSAR and Molecular docking approaches. Results indicate that, biological activity of SrtA inhibitors is closely related to the closed lid conformation of SrtA from Bacillus anthracis . This work may lead to a better understanding of the mechanism of action and aid to design a novel and more potent SrtA inhibitors.