Primary Structure of Protein L10 from the Large Subunit ofEscherichia coliRibosomes

Abstract

The complete primary structure of protein L10 from the large subunit of the E. coli ribosome was determined. L10 is composed of 165 residues and has the amino acid composition: Asp6, Asn3, Thr9, Ser6, Glu14, Gln4, Pro5, Gly9, Ala33, Val 15, Met5, Ile5, Leu15, Tyr3, Phe6, His1, Lys12, Arg13 and Cys1. The MW of L10 is 17,738. The amino acid sequence was determined by a combination of automated Edman degradation of the intact protein in a modified Beckman sequenator and sequencing peptides obtained from digestions with trypsin [EC 3.4.21.4], thermolysin [EC 3.4.24.4], Staphylococcus aureus protease and chymotrypsin [EC [EC 3.4.21.1]. Further information was obtained from CNBr fragments and peptides resulting from digestion with trypsin after protection of the .epsilon.-amino groups of the lysine residues with exo-cis-3,6-endoxo-.DELTA.4 tetrahydrophthalic anhydride (ETPA).