Article
- The EMBO Journal (2004) 23, 3187 - 3195
- doi:10.1038/sj.emboj.7600330
Published online: 22 July 2004
Subject Categories:
Crystal structure of the bacterial nucleoside transporter Tsx
Jiqing Ye1 and Bert van den Berg1,2
- Department of Cell Biology, Howard Hughes Medical Institute and Harvard Medical School, Boston, MA, USA
- Present address: University of Massachusetts Medical School, Program in Molecular Medicine, 373 Plantation Street, Worcester, MA 01605, USA
Correspondence to:
Bert van den Berg, Department of Cell Biology, Howard Hughes Medical Institute and Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA. Tel.: +1 617 432 0637; Fax: +1 617 432 1190; E-mail: bert.vandenberg@umassmed.edu or evandenberg@hms.harvard.edu
Received 18 May 2004; Accepted 24 June 2004
Abstract
Tsx is a nucleoside-specific outer membrane (OM) transporter of Gram-negative bacteria. We present crystal structures of Escherichia coli Tsx in the absence and presence of nucleosides. These structures provide a mechanism for nucleoside transport across the bacterial OM. Tsx forms a monomeric, 12-stranded 
-barrel with a long and narrow channel spanning the outer membrane. The channel, which is shaped like a keyhole, contains several distinct nucleoside-binding sites, two of which are well defined. The base moiety of the nucleoside is located in the narrow part of the keyhole, while the sugar occupies the wider opening. Pairs of aromatic residues and flanking ionizable residues are involved in nucleoside binding. Nucleoside transport presumably occurs by diffusion from one binding site to the next.
Keywords:
- binding site,
- crystal structure,
- ENT,
- nucleoside transporter,
- outer membrane protein
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated
NEWS AND VIEWS
Gliding through sugar channels: how sweet it is!
Nature Structural Biology News and Views (01 Jan 1998)
RESEARCH
Structure of the monomeric outer-membrane porin OmpG in the open and closed conformation
The EMBO Journal Article (09 Aug 2006)
Structure and function of the porin channel
Kidney International Original Article
Transmembrane passage of hydrophobic compounds through a protein channel wall
Nature Letters to Editor (19 Mar 2009)
