2WIT

CRYSTAL STRUCTURE OF THE SODIUM-COUPLED GLYCINE BETAINE SYMPORTER BETP FROM CORYNEBACTERIUM GLUTAMICUM WITH BOUND SUBSTRATE

Replaces:  2W8A

Summary for 2WIT

• Entry DOI: 10.2210/pdb2wit/pdb
• Related: 2W8A
• Descriptor: GLYCINE BETAINE TRANSPORTER BETP, TRIMETHYL GLYCINE (2 entities in total)
• Functional Keywords: membrane protein, chemosensor and osmosensor, trimer, membrane, transport, cell membrane, secondary transporter, sodium coupled transport, transmembrane, betaine transport, hyperosmotic stress
• Biological source: CORYNEBACTERIUM GLUTAMICUM
• Total number of polymer chains: 3
• Total formula weight: 185472.16

Authors

Ressl, S.,Terwisscha Van Scheltinga, A.C.,Vonrhein, C.,Ott, V.,Ziegler, C. (deposition date: 2009-05-17, release date: 2009-05-26, Last modification date: 2023-11-15)

Primary citation

Ressl, S.,Terwisscha Van Scheltinga, A.C.,Vonrhein, C.,Ott, V.,Ziegler, C.
Molecular Basis of Transport and Regulation in the Na(+)/Betaine Symporter Betp.
Nature, 458:47-, 2009

PubMed Abstract: Osmoregulated transporters sense intracellular osmotic pressure and respond to hyperosmotic stress by accumulation of osmolytes to restore normal hydration levels. Here we report the determination of the X-ray structure of a member of the family of betaine/choline/carnitine transporters, the Na(+)-coupled symporter BetP from Corynebacterium glutamicum, which is a highly effective osmoregulated uptake system for glycine betaine. Glycine betaine is bound in a tryptophan box occluded from both sides of the membrane with aromatic side chains lining the transport pathway. BetP has the same overall fold as three unrelated Na(+)-coupled symporters. Whereas these are crystallized in either the outward-facing or the inward-facing conformation, the BetP structure reveals a unique intermediate conformation in the Na(+)-coupled transport cycle. The trimeric architecture of BetP and the break in three-fold symmetry by the osmosensing C-terminal helices suggest a regulatory mechanism of Na(+)-coupled osmolyte transport to counteract osmotic stress.

PubMed: 19262666
DOI: 10.1038/NATURE07819

Experimental method

X-RAY DIFFRACTION (3.35 Å)