... observed between twoatoms (i,j), of types ti and tj, and Nobs(dij,ti,tj) represents thenumber of atoms of types ti and tjobserved in the structuretraining set, separated by a distance ... structure.Some RRM and KH domains in complex with singlestrand DNA (PDB codes: 2UP1, 1WTB, 1X0F, 1ZZI and 1ZZJ) were also included in the test set because recognition of single stranded RNA and DNA are ... proteins [6,39,40] and by the structure of existing KH domains bound to RNA[6,41–44]. As a consequence of the assumptions of the model, complexes containing two RNA-binding domains were divided...