ORGANIZATION OF THE CHICKEN ANNEXIN V GENE AND ITS CORRELATION WITH THE TERTIARY STRUCTURE OF THE PROTEIN

Chicken annexin V (anchorin CII) is a collagen binding, membrane-assoc iated molecule with Ca2+ channel activity. Here we report on the codin g sequences, promotor region, size and distribution of exons, and exon -intron junctions of the chicken annexin V gene. It is about 25 kb lon g and codes for 13 short exons between 50 and 581 bp length. Exon size s and locations of splice sites are almost completely homologous to th ose of the human and mouse annexin II or pigeon annexin I genes, altho ugh there is only 50-60% homology in the sequence of the corresponding proteins. The four repeat structure and symmetry of the annexin V as evident from sequence and X-ray analysis studies is only partially ref lected in this highly conserved exon distribution. In the first two re peats of chicken annexin V the exons correlate with protein domains co ntaining one, two, or three alpha-helices, while in the repeats 3 and 4 exon junctions and alpha-helical domains do not correlate. The analy sis of the promotor structure revealed the absence of a typical TATA-b ox, but a GC-rich region which may possibly promote transcription from several start sites.