BASE SPECIFICITY AND PRIMARY STRUCTURE OF POLY U-PREFERENTIAL RIBONUCLEASE FROM CHICKEN LIVER

The primary structure and base specificity of chicken liver RNase CL(1 ) which has been reported by Miura et al, [Chem. Pharm. Bull,, 32, 405 3-3060 (1983)] as poly U-preferential RNase. were extensively studied, The sequence study of this enzyme and comparison of the amino acid se quence of the enzyme with homologous RNases from oyster and Drosophila melanogaster suggested that RNase CL(1) consists of three peptides wi th 17, 19, and 163 amino acid residues, The amino acid sequence of the se three peptides were identified, The two small peptides are joined t o the large peptide by disulfide bridges, The amino acid sequence of R Nase CL(1) had 62 (31.2%) and 63 residues (31.6%) identical with oyste r RNase and D, melanogaster RNase, respectively, and belongs to the RN ase T-2 family RNase. Reassessment of the base specificity of RNase CL (1) found that it is guanylic acid, then uridylic acid-preferential, a nd not poly U preferential.