cDNA clones that span the full-length actin-binding protein homologue sequence. Clone K1.3 was isolated by the yeast two-hybrid screening, clones 1-4 were obtained by rapid amplification of 5′ cDNA ends (5′ RACE), and clones 5 and 6 were the cDNA clones isolated from a human placenta library. The diagram shows an alignment of the ABP cDNA with characteristic functional domains of the ABP subunit. The asterisk indicates the position of the 24 amino acid Hinge I insertion in ABP-278.