9PYM

Cryo-EM structure of the isethionate TRAP transporter IseQM from Oleidesulfovibrio alaskensis with bound isethionate

Summary for 9PYM

• Entry DOI: 10.2210/pdb9pym/pdb
• EMDB information: 72036
• Descriptor: Isethionate TRAP transporter permease protein DctMQ, Megabody C7HopQ, SODIUM ION, ... (5 entities in total)
• Functional Keywords: trap transporter, megabody, isethionate, transport protein
• Biological source: Oleidesulfovibrio alaskensis G20; More
• Total number of polymer chains: 2
• Total formula weight: 125407.71

Authors

Newton-Vesty, M.C.,Davies, J.S.,Dobson, R.C.J. (deposition date: 2025-08-07, release date: 2025-11-12, Last modification date: 2026-01-21)

Primary citation

Newton-Vesty, M.C.,Scalise, M.,Jamieson, S.A.,Currie, M.J.,Brown, H.G.,Valimehr, S.,Tillett, Z.D.,Hall, K.R.,Quan, S.,Allison, J.R.,Whitten, A.E.,Panjikar, S.,Indiveri, C.,Hanssen, E.,Mace, P.D.,North, R.A.,Dobson, R.C.J.,Davies, J.S.
Structural basis of isethionate transport by a TRAP transporter from a sulfate-reducing bacterium.
Structure, 34:133-, 2026

PubMed Abstract: Sulfate-reducing bacteria import organosulfur compounds from the environment for anaerobic respiration. They contribute to human disease and are problematic in industrial settings because they produce hydrogen sulfide. Here, we demonstrate how the sulfate-reducing bacterium Oleidesulfovibrio alaskensis imports isethionate, a common organosulfonate, using a tripartite ATP-independent periplasmic (TRAP) transporter (OaIsePQM). The cryo-EM structure of isethionate-bound OaIseQM to 2.98 Å resolution defines the substrate-binding site, two Na-binding sites, and a distinct fusion helix. Key residues within the OaIseQM substrate-binding site are identified using substitution and proteoliposome assays. Functional studies demonstrate that OaIseQM requires the substrate-binding protein (OaIseP) and a Na gradient to drive transport. Modeling of the OaIsePQM complex supports that elevator-type conformational changes are involved in this unique coupled transport process. This work expands our knowledge of the transport of organosulfur compounds in bacteria and establishes OaIsePQM as a new model system for exploring the mechanism of TRAP transporters.

PubMed: 41197622
DOI: 10.1016/j.str.2025.10.011

Experimental method

ELECTRON MICROSCOPY (2.98 Å)