Report

An Inward-Facing Conformation of a Putative Metal-Chelate-Type ABC Transporter

See allHide authors and affiliations

Science  19 Jan 2007:
Vol. 315, Issue 5810, pp. 373-377
DOI: 10.1126/science.1133488

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

The crystal structure of a putative metal-chelate–type adenosine triphosphate (ATP)–binding cassette (ABC) transporter encoded by genes HI1470 and HI1471 of Haemophilus influenzae has been solved at 2.4 angstrom resolution. The permeation pathway exhibits an inward-facing conformation, in contrast to the outward-facing state previously observed for the homologous vitamin B12 importer BtuCD. Although the structures of both HI1470/1 and BtuCD have been solved in nucleotide-free states, the pairs of ABC subunits in these two structures differ by a translational shift in the plane of the membrane that coincides with a repositioning of the membrane-spanning subunits. The differences observed between these ABC transporters involve relatively modest rearrangements and may serve as structural models for inward- and outward-facing conformations relevant to the alternating access mechanism of substrate translocation.

    View Full Text