Primary structure of an acidic ribosomal protein YPA1 from Saccharomyces cerevisiae

The complete primary structure of an acidic ribosomal protein YPA1 from Saccharomyces cerevisiae has been determined. YPA1 is composed of 110 amino acid residues and has the composition: Asp₇, Asn₂, Thr₂, Ser₉, Glu₁₅, Gln₂, Pro₃, Gly₁₅, Ala₂₁, Val₆, Met₂, Ile₄, Leu₉, Tyr₂, Phe₃, Lys₇ and Arg₁. The molecular weight of YPA1 is 11 020. The amino acid sequence was determined by $\text{4-N,N-}\text{dimethylaminoazobenzene}$ 4′-isothiocyanate degradation of the peptides obtained by digestions with trypsin, chymotrypsin, thermolysin, pepsin and Staphylococcus aureus protease of intact protein. A comparison of protein YPA1 from yeast with eL12 from Artemia salina shows a high sequence similarity. A considerable similarity is also shown with HL20 from Halobacterium cutirubrum. On the other hand, there is very little apparent sequence similarity between YPA1 and the eubacterial acidic protein L12 either from E. coli or B. subtilis.