Medical College of Wisconsin
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Apo structure of the ligand-binding domain of aspartate receptor from Escherichia coli and its comparison with ligand-bound or pseudoligand-bound structures. FEBS Lett 1997 Sep 08;414(2):327-32

Date

10/07/1997

Pubmed ID

9315712

DOI

10.1016/s0014-5793(97)01027-2

Scopus ID

2-s2.0-0031559942   32 Citations

Abstract

The aspartate receptor from E. coli is a dimeric transmembrane-signaling protein that mediates chemotaxis behavior and is the most studied system among the chemotaxis receptors to understand the molecular mechanism for transmembrane signaling. However, there is an unresolved issue for the structural event which initiates the transmembrane signal upon binding to the ligand. Biochemical and genetic evidence implies an intrasubunit mechanism (monomeric model) whereas crystallographic evidence implies an intersubunit mechanism (dimeric model). Crystallographic evidence has been ambiguous because all the apo protein structures contained a pseudoligand sulfate, and a completely ligand-free structure has not been available thus far. Here we present the crystal structure of the ligand binding domain of the aspartate receptor free of the ligand aspartate or pseudoligand sulfate. The structural comparison of this structure with those of ligand-bound and pseudoligand-bound forms revealed that, on ligand or pseudoligand binding, the conformational change in the ligand-binding domain is relatively small, but there is a considerable rotation between two subunits, supporting the dimeric model.

Author List

Chi YI, Yokota H, Kim SH

Author

Young-In Chi PhD Assistant Professor in the Surgery department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Apoproteins
Aspartic Acid
Binding Sites
Cell Membrane
Chemotaxis
Computer Simulation
Crystallography
Dimerization
Escherichia coli
Ligands
Models, Molecular
Models, Structural
Protein Conformation
Receptors, Amino Acid
Signal Transduction
Software
Structure-Activity Relationship