Binding Site

IQ motif, EF-hand binding site (IPR000048)

Short name: IQ_motif_EF-hand-BS

Description

The IQ motif is an extremely basic unit of about 23 amino acids, whose conserved core usually fits the consensus A-x(3)-I-Q-x(2)-F-R-x(4)-K-K. The IQ motif, which can be present in one or more copies, serves as a binding site for different EF-hand proteins including the essential and regulatory myosin light chains, calmodulin (CaM), and CaM-like proteins [PMID: 1558751, PMID: 9141499].Many IQ motifs are protein kinase C (PKC) phosphorylation sites [PMID: 1824695, PMID: 8424932].

Resolution of the 3D structure of scallop myosin has shown that the IQ motif forms a basic amphipathic helix [PMID: 8127365].

Some proteins known to contain an IQ motif are listed below:

  • A number of conventional and unconventional myosins.
  • Neuromodulin (GAP-43). This protein is associated with nerve growth. It is a major component of the motile "growth cones" that form the tips of elongating axons.
  • Neurogranin (NG/p17). Acts as a "third messenger" substrate of protein kinase C-mediated molecular cascades during synaptic development and remodeling.
  • Sperm surface protein Sp17.
  • Ras GTPase-activating-like protein IQGAP1. IQGAP1 contains 4 IQ motifs.

This entry covers the entire IQ motif.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005515 protein binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
SMART
PROSITE profiles
Pfam