Chiral recognition of 2,3-dihydroxypropanesulfonate by bacterial transport proteins adapted to distinct ecological niches

Abstract

Bacterial catabolism of 2,3-dihydroxypropanesulfonate (DHPS) links algal production to marine degradation and connects sulfosugar metabolism to sulfide production in the gut. In surface seawater, DHPS occurs as a dilute, mixed R/S pool, whereas in the anaerobic gut it is produced predominantly as S-DHPS through bacterial sulfoglycolysis pathways. Uptake is achieved via tripartite ATP-independent periplasmic (TRAP) transporters that employ periplasmic substrate-binding proteins (HpsK), but the molecular basis of enantiomer recognition has not been defined. Here, we compare HpsK proteins from the marine bacterium Ruegeria pomeroyi and the gut anaerobe Bilophila wadsworthia using proteomics, bi..