A novel model of the dimeric hHv1 channel reveals a putative ATP binding site

LLANOS MANUEL; MARTIN PEDRO; ENRIQUE NICOLAS; FELICE JUAN; ASUAJE AGUSTÍN; GAVERNET LUCIANA; MILESI VERONICA; VENTURA CLARA

Congreso; 65TH Biophysical Society Annual Meeting; 2021

A multi-template model of the voltage-gated proton channel (hHv1) was developed by combining the recently solved NMR structural ensemble of the hHv1 (PDBID: 5OQK) with the coiled-coil C-terminal domain (PDBID: 3A2A), bridging them through the chimeric mHv1cc structure (PDBID: 3WKV). The model was built and refined as a dimer within Rosetta?s Membrane framework, using the symmetry extracted from the coiled-coil and including experimentally derived constraints during the relaxation.The dimeric model was then subjected to extensive Gaussian Accelerated Molecular Dynamics simulations in a POPC bilayer, and representative snapshots were extracted from the trajectory by clustering analysis. Blind docking simulations of an ATP molecule on this structural ensemble revealed a putative ATP binding site located on the intracellular portion of the permeation pathway, below R3 (ARG211). The same region was identified by two sequence-based ATP binding site predictors: ATPSite and ATPint; and a third meta-predictor which combines sequence and structure-based features: ATPBind.