The primary structures of rat ribosomal proteins: the characterization of the cDNAs for S21 and L39, corrections in the sequences of L7 and L18a, and the identification of L33.

cDNAs for rat ribosomal proteins S21 and L39 were characterized. S21 has 83 amino acids and a molecular weight of 9,121; L39 has 50 amino acids and a molecular weight of 6,271. There are 8 to 9 copies of the S21, and 9 to 11 copies of the L39 genes. The mRNA for S21 is about 500 nucleotides in length and for L39 it is about 450. Rat S21 and L39 are related to ribosomal proteins from other species. Corrections have been made in the amino acid sequences of L7 and L18a. The rat ribosomal protein designated L33 from its coordinates on two-dimensional gels has been found, from its amino acid sequence, to be identical to S24.