Video Experimental Relacionado

Updated: Feb 22, 2026

Characterization of Membrane Transporters by Heterologous Expression in E. coli and Production of Membrane Vesicles

Characterization of Membrane Transporters by Heterologous Expression in E. coli and Production of Membrane Vesicles

Published on: December 31, 2019

Los enlaces de hidrógeno CH•••S impulsan el reconocimiento molecular de la ergotionina por el transportador

Katherine A Legg¹, Giovanni Gonzalez-Gutierrez², Katherine A Edmonds¹

¹Department of Chemistry, Indiana University, Bloomington, IN, USA.

Science advances

|February 20, 2026

Abstract:

Many bacteria harbor an ATP-binding cassette (ABC) transporter named EgtU specific for the human dietary antioxidant and 2-thioimidazole-containing low-molecular weight thiol ergothioneine (ET). How the solute binding domain, EgtUC, discriminates among ET and other similar molecules is unknown. Here, we use a "chimeric" mutagenesis strategy and two distantly related EgtUCs from Streptococcus pneumoniae and Helicobacter pylori to show that a suite of EgtUC alkyl CH•••S hydrogen bonds to the ET thione S atom are central determinants of molecular recognition. Small perturbations in CH•••S distance and angle give rise to sharply attenuated transport-competent ET-bound "closed" state lifetimes and increased motional disorder in the binding pocket, not around the S atom itself, but distally in weakening NH•••O hydrogen bonds. This work highlights the impact of alkyl CH•••S H bonding in a biological protein-ligand complex in water.

Palabras clave:

ergotionina transportadores ABC enlaces de hidrógeno CH•••S reconocimiento molecular microbiología

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