Evolution of the multidomain protein wheat germ agglutinin

摘要: We compared the homologous amino acid sequences of hevein and each four domains (A, B, C, D) wheat germ agglutinin used them to construct a pseudophylogenetic tree relating these hypothetical common ancestor sequence. In crystal structure dimer, six pseudo-twofold rotational symmetry axes have previously been located in addition true twofold axis. Four relate two nonidentical other possible pairs constituting sugar-binding sites (A1D2, A2D1, B1C2, B2C1). The remaining contiguous unique (A1D2 A2D1 These latter sets are related by Side chains that mediate sugar binding interfaces were found be largely conserved. sequence homology, taken together with pseudo-symmetry elements dimer structure, suggests pathway for evolution four-domain molecule from single-domain can correlated simultaneous development saccharide-binding sites.