... that tetramer formationdepends upon contact of b-strand 10 from the C-ter-minal extensions of monomers A and D withb-strands 4 and 8 in the a-crystallin domain of monomers C and B, respectively ... panels A and B received 4.5–5.5 lg of protein and lanes in pan-els C and D received 1 lg of protein. Arrow, p26. M, molecular mass markers of 97, 66, 45, 31, 21 and 14 kDa.a-crystallin domain of ... occurs with b-strand 7 of monomer B interacting with loop L5 ⁄ 7 of mono-mer C, and b-strand 7 of monomer C reacting withL5 ⁄ 7 of monomer B, regions of high similaritybetween p26 and Hsp16.9 (Fig....