Domain structures of representative annexin proteins. Orthologs of the 12 human annexins shown in other vertebrates have the same structures, with strict conservation of the four repeats in the core region (black) and variation in length and sequence in the amino-terminal regions (shaded). Human ANXA1 and ANXA2 are shown as dimers, with the member of the S100 protein family that they interact with. Domain structures for other model organisms are derived from public data made available by the relevant genome-sequencing projects. Features: S100Ax, sites for attachment of the indicated member of the S100 family of calcium-binding proteins; P, known phosphorylation sites; K, KGD synapomorphy (a conserved, inherited characteristic of proteins); I, codon insertions (+x denotes the number of codons inserted); S-A/b, nonsynonymous coding polymorphisms (SNPs) with the amino acid in the major variant (A) and that in the minor variant (b); N, putative nucleotide-binding sites; D, codon deletions (-x denotes the number of codons deleted); A, alternatively spliced exons; Myr, myristoylation. The total length of each protein is indicated on the right.