Journal of Molecular Evolution

, Volume 46, Issue 4, pp 389–400

The immunoglobulin superfamily: An insight on its tissular, species, and functional diversity


DOI: 10.1007/PL00006318

Cite this article as:
Halaby, D.M. & Mornon, J.P.E. J Mol Evol (1998) 46: 389. doi:10.1007/PL00006318


The immunoglobulin superfamily (IgSF) is a heterogenic group of proteins built on a common fold, called the Ig fold, which is a sandwich of two ßp sheets. Although members of the IgSF share a similar Ig fold, they differ in their tissue distribution, amino acid composition, and biological role.

In this paper we report an up-to-date compilation of the IgSF where all known members of the IgSF are classified on the basis of their common functional role (immune system, antibiotic proteins, enzymes, cytokine receptors, etc.) and their distribution in tissue (neural system, extracellular matrix, tumor marker, muscular proteins, etc.), or in species (vertebrates, invertebrates, bacteria, viruses, fungi, and plants). The members of the family can contain one or many Ig domains, comprising two basic types: the constant domain (C), with seven strands, and the variable domain (V), with eight, nine, or ten strands. The different overviews of the IgSF led to the definition of new domain subtypes, mainly concerning the C type, based on the distribution of strands within the two sheets.

The wide occurrence of the Ig fold and the much less conserved sequences could have developed from a common ancestral gene and/or from a convergent evolutionary process. Cell adhesion and pattern recognition seem to be the common feature running through the entire family.

Key Words

Proteins familiesImmunoglobulin foldDomainsFibronectin type IIIEvolutionFunctionConstant domainsVariable domains



constant domain


fibronectin III




Immunoglobulin superfamily


variable domain

Copyright information

© Springer-Verlag New York Inc 1998

Authors and Affiliations

  1. 1.Systàmes Moléculaires et Biologie Structurale, LMCP, CNRS URA 09Université Pierre et Marie-CurieParis cedex 05France