View source for 24gh


==Crystal structure of HpsK from Bilophila wadsworthia in complex with S-DHPS (2,3-dihydroxypropanesulfonate)==
<StructureSection load='24gh' size='340' side='right'caption='[[24gh]], [[Resolution|resolution]] 1.05&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[24gh]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Bilophila_wadsworthia_3_1_6 Bilophila wadsworthia 3_1_6]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=24GH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=24GH FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.05&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=LLQ:(2~{S})-2,3-bis(oxidanyl)propane-1-sulfonic+acid'>LLQ</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=24gh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=24gh OCA], [https://pdbe.org/24gh PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=24gh RCSB], [https://www.ebi.ac.uk/pdbsum/24gh PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=24gh ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
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, biophysical analysis, X-ray crystallography, and bioinformatics. RpHpsK binds both R- and S-DHPS with low-nanomolar affinity (K (D) 5-9 nM), whereas BwHpsK binds selectively to S-DHPS (K (D) 530 nM), representing an approximately 100-fold difference in affinity and strict stereoselectivity. Crystal structures reveal two contrasting strategies for chiral recognition: RpHpsK accommodates both enantiomers through subtle side-chain "toggling" within an otherwise conserved binding pocket, whereas BwHpsK achieves stereoselectivity through a distinct hydrogen-bonding network and a binding site that sterically excludes R-DHPS. Sequence similarity and genome neighbourhood analyses place these proteins in separate clusters associated with oxidative (HpsNOP) or glycyl radical enzyme-linked (HpsGH/HpfGH) pathways. These findings show how changes in binding-site architecture tune ligand stereoselectivity and illustrate the adaptation of TRAP-associated substrate binding proteins to distinct ecological and metabolic niches.

Chiral recognition of 2,3-dihydroxypropanesulfonate by bacterial transport proteins adapted to distinct ecological niches.,Barber H, Borusak S, Stewart AWE, Tahir H, Scott NE, Schleheck D, Lee M, Williams SJ Chem Sci. 2026 Jun 19;17(32):15566-15579. doi: 10.1039/d6sc02372j. eCollection , 2026 Aug 19. PMID:42441157<ref>PMID:42441157</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
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</StructureSection>
[[Category: Bilophila wadsworthia 3_1_6]]
[[Category: Large Structures]]
[[Category: Lee M]]