Fig. 4

Conformation  of the sequence Lys-31-Ser32-Arg-33 at the end of alpha helix II (a) Orthorhombic RNase and (b) 3RN3. Details: a Orthorhombic RNase A Lys31-Ser32-Arg33 sequence showing the major (62.6%) conformation and minor (blue) (37.4%) conformation of Lys-31 and the major A conformation of Ser32 (76%) and minor conformation (blue) (24%) (Drawn with Biovia [19]; b Monoclinic RNase A 3RN3 [5] (Drawn with Biovia [19]); c Orthorhombic Ribonuclease A Lys-31A -Ser-32-Arg-33 sequence showing Ser-32 A (major 76%) and B (minor 24%) conformations. Drawn with MERCURY [20]. Note: The Major conformation of Orthorhombic Ser-32A is very similar to that of Ser-32 in 3RN3 [5]. b The main chain conformations of this sequence are characterised by significant differences as shown in Table 3 below