Format

Send to

Choose Destination
See comment in PubMed Commons below
Nat Struct Biol. 1996 Jan;3(1):67-73.

Structure of a novel extracellular Ca(2+)-binding module in BM-40.

Author information

1
Department of Structural Biology, University of Basel, Switzerland.

Abstract

The EF-hand is a highly conserved Ca(2+)-binding motif found in many cytosolic Ca(2+)-modulated proteins. Here we report the crystal structure at 2.0 A resolution of the carboxy-terminal domain of human BM-40 (SPARC, osteonectin), an extracellular matrix protein containing an EF-hand pair. The two EF-hands interact canonically but their detailed structures are unusual. In the first EF-hand a one-residue insertion is accommodated by a cis-peptide bond and by substituting a carboxylate by a peptide carbonyl as a Ca2+ ligand. The second EF-hand is stabilized by a disulphide bond. The EF-hand pair interacts tightly with an amphiphilic amino-terminal helix, reminiscent of target peptide binding by calmodulin. The present structure defines a novel protein module occurring in several other extracellular proteins.

PMID:
8548457
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center