A NOVEL STRUCTURAL MOTIF AND STRUCTURAL TREES FOR PROTEINS CONTAINING IT
In the present study, a novel structural motif that can be represented as a combination of the known βαβ-unit and ψ-motif is described and analyzed. In theory, there are four possible combinations of the motifs since each of them can exist in two forms, left-handed and right-handed. For this study, we selected 140 non-homologous proteins in which 158 combinations of such types have been found. The combination of the right-hand ψ-motif is shown to occur most often (87 cases of 158) and the combination of the left-handed βαβ-unit and the left-handed ψ-motif does not occur at all. Three novel structural trees in which the commonly occurring combinations are taken as root structures have been constructed.