A novel structural tree for wrap-proteins, a subclass of (α+ß)-proteins.

In this paper, a novel structural subclass of (α+ß)-proteins is presented. A characteristic feature of these proteins and domains is that they consist of strongly twisted and coiled ß-sheets wrapped around one or two α-helices, so they are referred to here as wrap-proteins. It is shown that overall folds of the wrap-proteins can be obtained by stepwise addition of α-helices and/or ß-strands to the strongly twisted and coiled ß-hairpin taken as the starting structure in modeling. As a result of modeling, a structural tree for the wrap-proteins was constructed that includes 201 folds of which 49 occur in known nonhomologous proteins.