Newly observed binding mode in pancreatic ribonuclease.

Dinucleotides containing guanine, when soaked into crystals of bovine pancreatic ribonuclease, have been found to bind in an unexpected manner, quite unlike interpretations of earlier X-ray diffraction studies. This finding has prompted a reexamination of three mononucleotide-RNase complexes from this laboratory resulting in a re-interpretation of the complex that involved a guanine mononucleotide.