3PUY: Crystal Structure Of An Outward-Facing Mbp-Maltose Transporter Complex Bound To Amp-Pnp After Crystal Soaking Of The Pretranslocation State

Citation:
Abstract
Adenosine triphosphate (ATP)-binding cassette (ABC) transporters convert chemical energy from ATP hydrolysis to mechanical work for substrate translocation. They function by alternating between two states, exposing the substrate-binding site to either side of the membrane. A key question that remains to be addressed is how substrates initiate the transport cycle. Using x-ray crystallography, we have captured the maltose transporter in an intermediate step between the inward- and outward-facing states. We show that interactions with substrate-loaded maltose-binding protein in the periplasm induce a partial closure of the MalK dimer in the cytoplasm. ATP binding to this conformation then promotes progression to the outward-facing state. These results, interpreted in light of biochemical and functional studies, provide a structural basis to understand allosteric communication in ABC transporters.
PDB ID: 3PUYDownload
MMDB ID: 90632
PDB Deposition Date: 2010/12/6
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 3.1  Å
Source Organism:
Similar Structures:
Biological Unit for 3PUY: pentameric; determined by author and by software (PISA)
Molecular Components in 3PUY
Label Count Molecule
Proteins (5 molecules)
1
Maltose Transporter Subunit; Periplasmic-binding Component of ABC Superfamily
Molecule annotation
1
Maltose Transporter Subunit; Membrane Component of ABC Superfamily
Molecule annotation
1
Maltose Transporter Subunit; Membrane Component of ABC Superfamily
Molecule annotation
2
Fused Maltose Transport Subunit, Atp-binding Component of ABC Superfamily; Regulatory Protein
Molecule annotation
Chemicals (6 molecules)
1
1
2
1
3
2
4
2
* Click molecule labels to explore molecular sequence information.

Citing MMDB
.