Tertiary structure of RNase Pch1 predicted from the model structure of RNase Ms and the crystal structure of RNase T1. Comparison among the model structures--testing the limits of modelling by homology.

In this paper we predict the structure of RNase Pch1 as modelled from the previously predicted structure of RNase Ms and the crystal structure of RNase T1 in the complex with 2'GMP. The predicted structures and their initial energy minimized structural RNase T1 template are compared. The predicted structures of RNase Pch1 show, independent of their prediction form RNase Ms or T1, a higher structural similarity to RNase T1 than to RNase Ms, in agreement with higher sequence similarity and specificity - RNases T1 and Pch1 are specific for guanine whereas RNase Ms is base-unspecific with preference for guanine.