3llo
From Proteopedia
Contents |
Crystal structure of the STAS domain of motor protein prestin (anion transporter SLC26A5)
Template:ABSTRACT PUBMED 20471983
Function
[S26A5_RAT] Motor protein that converts auditory stimuli to length changes in outer hair cells and mediates sound amplification in the mammalian hearing organ. Prestin is a bidirectional voltage-to-force converter, it can operate at microsecond rates. It uses cytoplasmic anions as extrinsic voltage sensors, probably chloride and bicarbonate. After binding to a site with millimolar affinity, these anions are translocated across the membrane in response to changes in the transmembrane voltage. They move towards the extracellular surface following hyperpolarization, and towards the cytoplasmic side in response to depolarization. As a consequence, this translocation triggers conformational changes in the protein that ultimately alter its surface area in the plane of the plasma membrane. The area decreases when the anion is near the cytoplasmic face of the membrane (short state), and increases when the ion has crossed the membrane to the outer surface (long state). So, it acts as an incomplete transporter. It swings anions across the membrane, but does not allow these anions to dissociate and escape to the extracellular space. Salicylate, an inhibitor of outer hair cell motility, acts as competitive antagonist at the prestin anion-binding site (By similarity).
About this Structure
3llo is a 1 chain structure with sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
- Pasqualetto E, Aiello R, Gesiot L, Bonetto G, Bellanda M, Battistutta R. Structure of the cytosolic portion of the motor protein prestin and functional role of the STAS domain in SLC26/SulP anion transporters. J Mol Biol. 2010 Jul 16;400(3):448-62. Epub 2010 May 21. PMID:20471983 doi:10.1016/j.jmb.2010.05.013
