Format

Send to

Choose Destination
See comment in PubMed Commons below
Nat Struct Mol Biol. 2012 Jan 15;19(2):207-11. doi: 10.1038/nsmb.2197.

Experimental conditions can obscure the second high-affinity site in LeuT.

Author information

1
Center for Molecular Recognition, Columbia University College of Physicians and Surgeons, New York, New York, USA.

Abstract

Neurotransmitter:Na(+) symporters (NSSs), the targets of antidepressants and psychostimulants, recapture neurotransmitters from the synapse in a Na(+)-dependent symport mechanism. The crystal structure of the NSS homolog LeuT from Aquifex aeolicus revealed one leucine substrate in an occluded, centrally located (S1) binding site next to two Na(+) ions. Computational studies combined with binding and flux experiments identified a second substrate (S2) site and a molecular mechanism of Na(+)-substrate symport that depends upon the allosteric interaction of substrate molecules in the two high-affinity sites. Here we show that the S2 site, which has not yet been identified by crystallographic approaches, can be blocked during preparation of detergent-solubilized LeuT, thereby obscuring its crucial role in Na(+)-coupled symport. This finding points to the need for caution in selecting experimental environments in which the properties and mechanistic features of membrane proteins can be delineated.

Comment in

PMID:
22245968
PMCID:
PMC3272158
DOI:
10.1038/nsmb.2197
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Nature Publishing Group Icon for PubMed Central
    Loading ...
    Support Center