THE PRIMARY STRUCTURE OF RAT RIBOSOMAL-PROTEIN S23

The amino acid sequence of the rat 40S ribosomal subunit protein S23 w as deduced from the sequence of nucleotides in a recombinant cDNA. Rib osomal protein S23 has 142 amino acids, the NH2-terminal methionine is removed after translation of the mRNA, and a molecular weight of 15,6 66. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 6 to 13 copies of the S23 gene. The mRNA for the protein is about 650 nucleotides in length. Rat S23 is identical to a human ribos omal protein and is also related to Saccharomyces cerevisiae S28, to T etrahymena thermophila S12, and to the prokaryotic S12 family of ribos omal proteins. (C) 1994 Academic Press, Inc.