Abstract
A corrected amino acid sequence of rat pancreatic ribonuclease is presented which is in agreement with the messenger RNA sequence in [J. Biol. Chem. (1982) 257, 14582–14585]. The corrections do not change the general position of rat ribonuclease in trees which can be constructed for ribonuclease sequences, although they do place the rat sequence somewhat closer to the mouse sequence. The evolutionary rate of ribonuclease in the rodent family of the Muridae (rat and mouse) now has been calculated to be 140 nucleotide substitutions per 108 years per 100 codons, and still is one of the highest rates yet observed. The occurrence of 4 additional amino acids at the C-terminus in several mammalian ribonucleases is in agreement with the position of a second stop codon in the 3' non-coding region of the rat messenger RNA sequence.