Crystal structure of truncated human apolipoprotein A-I suggests a lipid-bound conformation

Academic Article

Abstract

  • The structure of truncated human apolipoprotein A-I (apo A-I), the major protein component of high density lipoprotein, has been determined at 4-Å resolution. The crystals comprise residues 44-243 (exon 4) of apo A-I, a fragment that binds to lipid similarly to intact apo A-I and that retains the lipid-bound conformation even in the absence of lipid. The molecule consists almost entirely of a pseudo-continuous, amphipathic α-helix that is punctuated by kinks at regularly spaced proline residues; it adopts a shape similar to a horseshoe of dimensions 125 x 80 x 40 Å. Four molecules in the asymmetric unit associate via their hydrophobic faces to form an antiparallel four-helix bundle with an elliptical ring shape. Based on this structure, we propose a model for the structure of apo A-I bound to high density lipoprotein.
  • Digital Object Identifier (doi)

    Author List

  • Borhani DW; Rogers DP; Engler JA; Brouillette CG
  • Start Page

  • 12291
  • End Page

  • 12296
  • Volume

  • 94
  • Issue

  • 23