EF hand

EF hand

Structure of the recombinant Paramecium tetraurelia calmodulin.[1]
Identifiers
Symbol efhand
Pfam PF00036
InterPro IPR002048
PROSITE PDOC00018
SCOP 1osa
SUPERFAMILY 1osa
OPM protein 1djx
CDD cd00051

The EF hand is a helix-loop-helix structural domain or motif found in a large family of calcium-binding proteins.

The EF-hand motif contains a helix-loop-helix topology, much like the spread thumb and forefinger of the human hand, in which the Ca2+ ions are coordinated by ligands within the loop. The motif takes its name from traditional nomenclature used in describing the protein parvalbumin, which contains three such motifs and is probably involved in muscle relaxation via its calcium-binding activity.

The EF-hand consists of two alpha helices linked by a short loop region (usually about 12 amino acids) that usually binds calcium ions. EF-hands also appear in each structural domain of the signaling protein calmodulin and in the muscle protein troponin-C.


Calcium ion binding site

EF-hand Ca2+ binding motif.

Prediction

Summary of motif signatures used for prediction of EF-hands.

Classification

Additional points:

Phylogenetic tree of the EF-hand protein family.

Subfamilies

Examples

Aequorin

Aequorin is a calcium binding protein (CaBP) isolated from the coelenterate Aequorea victoria. Aequorin belongs to the EF-hand family of CaBPs, with EF-hand loops that are closely related to CaBPs in mammals. In addition, aequorin has been used for years as an indicator of Ca2+ and has been shown to be safe and well tolerated by cells. Aequorin is made up of two components – the calcium binding component apoaequorin (AQ) and the chemiluminescent molecule coelenterazine. The AQ portion of this protein contains the EF-hand calcium binding domains.[2]

Human proteins

Humans proteins containing this domain include:

See also

References

  1. Ban C, Ramakrishnan B, Ling KY, Kung C, Sundaralingam M (January 1994). "Structure of the recombinant Paramecium tetraurelia calmodulin at 1.68 A resolution". Acta Crystallogr. D Biol. Crystallogr. 50 (Pt 1): 50–63. doi:10.1107/S0907444993007991. PMID 15299476.
  2. Detert JA, Adams EL, Lescher JD, Lyons JA, Moyer JR (2013). "Pretreatment with Apoaequorin Protects Hippocampal CA1 Neurons from Oxygen-Glucose Deprivation". PLoS ONE 8 (11): e79002. doi:10.1371/journal.pone.0079002. PMC 3823939. PMID 24244400.

Further reading

External links

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