9KMI

Taurine bound mTAUT

Summary for 9KMI

• Entry DOI: 10.2210/pdb9kmi/pdb
• EMDB information: 62434
• Descriptor: Sodium- and chloride-dependent taurine transporter, Heavy chain of 9D5 Fab, Light chain of 9D5 Fab, ... (7 entities in total)
• Functional Keywords: transporter, taurine, chlorine, sodium, membrane protein/immune system, membrane protein-immune system complex
• Biological source: Mus musculus (house mouse); More
• Total number of polymer chains: 3
• Total formula weight: 94877.81

Authors

She, J.,Wang, M.,He, J. (deposition date: 2024-11-16, release date: 2025-07-02, Last modification date: 2025-07-16)

Primary citation

Wang, M.,He, J.,Cai, Q.,Zhang, S.A.,She, J.
Molecular basis for substrate recognition and transport of mammalian taurine transporters.
Proc.Natl.Acad.Sci.USA, 122:e2425549122-e2425549122, 2025

PubMed Abstract: The taurine transporter (TAUT) mediates cellular taurine uptake, playing a critical role in human health and longevity. In this study, we present cryogenic electron microscopy structures of both mouse and human TAUT in various conformational states. The taurine-bound, occluded forms of mouse and human TAUT reveal the substrate binding pocket and the ion binding sites. The amino group of taurine interacts with Glu406 at the binding site, constituting a key structural feature determining substrate preference. While both imidazole acetic acid and guanidinoethyl sulfonate (GES) inhibit TAUT by competing with taurine for the binding site, GES also functions as a substrate of TAUT. Moreover, mouse TAUT is captured in an inward-open apo conformation, where the tilted movement of transmembrane helix (TM) 1a opens the intracellular gate. Notably, TM6 exhibits two distinct conformational states: the canonical form consisting of two half-helices and a continuous straight helix. In the latter conformation, TM6 partially occupies the substrate binding site, likely promoting taurine release. Together, our findings provide critical insights into the molecular mechanisms by which TAUT recognizes and transports taurine.

PubMed: 40601627
DOI: 10.1073/pnas.2425549122

Experimental method

ELECTRON MICROSCOPY (3.05 Å)