Ribosomal proteins

50-S Ribosomal Proteins. Purification and Partial Characterization of Two Acidic Proteins, A1 and A2, Isolated from 50-S Ribosomes of Escherichia coli

“…Slightly higher physical molecular weights of about 14000 have been reported for L,-and L,,-protein by Dzionara et al [6] but the difference between their data and the ones reported here are probably not significant. Examination of the amino acid composition of A,-and A,-protein shows that there is good agreement with the compositions of the proteins L, and L,, reported by KaltSchmidt et al [3]. It should be noted that the agreement with an earlier report from this laboratory [2] is less.…”

“…Both proteins give the same composition and the compositions agree well with those of the proteins L, and L,, studied by KaltSchmidt, Dzionara and Wittmann [3]. The amino acids tyrosine, cysteine and tryptophan are absent in pure protein and the amount of phosphorus was found well below I molecule of phosphorus per polypeptide chain.…”

“…I n addition an enumeration is given of some of the structural properties of A,-and A,-protein among physical molecular weight, number of copies per ribosome, isoelectric points and amino acid composition. The results are in general agreement with those obtained by the group of Wittmann on their proteins L, and L,, [3,5,6]. The structural and functional implications of our studies are briefly discussed.…”

Purification and Characterization of 50-S Ribosomal Proteins of Escherichia coli

“…This interpretation is supported by the following observations : first, the material appears homogeneous on dodecylsulfate gel ; second, no methionine can be detected in this protein, a very improbable result if the protein were contaminated, since almost all the ribosomal proteins contain this amino acid [7] ; third, the molecular weight calculated from the tryptic fingerprint and the amino acid composition is in good agreement with the physical molecular weight ( Table 3).…”

Synthesis of ribosomal proteins in λrifd18 infected minicells of escherichia coli and selective incorporation into ribosomes

“…[21]). Protein Ll showed the weakest spot and, on a relative molar scale using the similar ratio of methionine to total amino acids [22], it must be present in an even lesser amount since the molecular weight of Ll is considerably higher than that of the other ribosomal proteins [23]. The electrophoretic pattern ofnative 50 S subunits ( fig.3B) showed all 4 proteins but the spot of L7/L12 by far dominated the picture.…”