TUTCRIS

TY - JOUR

T1 - Atomic-level characterization of transport cycle thermodynamics in the glycerol-3-phosphate

T2 - Phosphate antiporter

AU - Moradi, Mahmoud

AU - Enkavi, Giray

AU - Tajkhorshid, Emad

PY - 2015/9/29

Y1 - 2015/9/29

N2 - Membrane transporters actively translocate their substrate by undergoing large-scale structural transitions between inward-(IF) and outward-facing (OF) states ('alternating-access' mechanism). Despite extensive structural studies, atomic-level mechanistic details of such structural transitions, and as importantly, their coupling to chemical events supplying the energy, remain amongst the most elusive aspects of the function of these proteins. Here we present a quantitative, atomic-level description of the functional thermodynamic cycle for the glycerol-3-phosphate:phosphate antiporter GlpT by using a novel approach in reconstructing the free energy landscape governing the IFâ †"OF transition along a cyclic transition pathway involving both apo and substrate-bound states. Our results provide a fully atomic description of the complete transport process, offering a structural model for the alternating-access mechanism and substantiating the close coupling between global structural transitions and local chemical events.

AB - Membrane transporters actively translocate their substrate by undergoing large-scale structural transitions between inward-(IF) and outward-facing (OF) states ('alternating-access' mechanism). Despite extensive structural studies, atomic-level mechanistic details of such structural transitions, and as importantly, their coupling to chemical events supplying the energy, remain amongst the most elusive aspects of the function of these proteins. Here we present a quantitative, atomic-level description of the functional thermodynamic cycle for the glycerol-3-phosphate:phosphate antiporter GlpT by using a novel approach in reconstructing the free energy landscape governing the IFâ †"OF transition along a cyclic transition pathway involving both apo and substrate-bound states. Our results provide a fully atomic description of the complete transport process, offering a structural model for the alternating-access mechanism and substantiating the close coupling between global structural transitions and local chemical events.

UR - http://www.scopus.com/inward/record.url?scp=84942854331&partnerID=8YFLogxK

U2 - 10.1038/ncomms9393

DO - 10.1038/ncomms9393

M3 - Article

VL - 6

JO - Nature Communications

JF - Nature Communications

SN - 2041-1723

M1 - 8393

ER -