Transporters are targeted by endogenous metabolites and exogenous molecules to reach cellular destinations. More importantly, atomistic detail as to how different substrate classes exploit the same transporter’s molecular mechanism is lacking. Thus, any disclosure of plasticity in transporter mechanism when treated with different substrates is critical for the development of selectivity principles in membrane transport catalysis. Here, using extensive molecular dynamics simulations, we select the <i>Arabidopsis</i> sugar transporter AtSWEET13 as a model system to identify the basis for glucose versus sucrose molecular recognition and transport. We find that AtSWEET13 demonstrates a conserved substrate facial selectivity when committing alternate access, despite mono- and di-saccharides experiencing differing degrees of conformational and positional freedom during early recognition events along the inward-facing channel. In summary, our results offer insights into (1) how cofactor-independent transporters accommodate different substrates within the same general transport scheme and (2) how transport selectivity can be engineered.

Bifurcating molecular recognition paths reveal mechanism for discriminating sugar transport

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.