Anion pathway and potential energy profiles along curvilinear bacterial ClC Cl- pores: electrostatic effects of charged residues.

ABSTRACT: X-ray structures permit theoretical study of Cl(-) permeation along bacterial ClC Cl(-) pores. We determined the lowest energy curvilinear pathway, identified anion-coordinating amino acids, and calculated the electrostatic potential energy profiles. We find that all four bacterial ClC Cl(-) crystal structures correspond to closed states. E148 and S107 side chains form steric barriers on both sides of the crystal binding site in the StClC wild-type and EcClC wild-type crystals; both the EcClC(E148A) and EcClC(E148Q) mutants are blocked at the S107 site. We studied the effect that mutating the charge of some strongly conserved pore-lining amino acids has on the electrostatic potential energy profiles. When E148 is neutralized, it creates an electrostatic trap, binding the ion near midmembra

SUBMITTER: Miloshevsky GV 

PROVIDER: S-EPMC1303930 | biostudies-literature | 2004 Feb

REPOSITORIES: biostudies-literature