ABSTRACT
The sequence of the amino-terminal region of eleven rat liver ribosomal proteins--S4, S6, S8, L6, L7a, L18, L27, L30, L37a, and L39--was determined. The analysis confirmed the homogeneity of the proteins and suggests that they are unique, since no extensive common sequences were found. The N-terminal regions of the rat liver proteins were compared with amino acid sequences in Saccharomyces cerevisiae and in Escherichia coli ribosomal proteins. It seems likely that the proteins L37 from rat liver and Y55 from yeast ribosomes are homologous. It is possible that rat liver L7a or L37a or both are related to S cerevisiae Y44, although the similar sequences are at the amino-terminus of the rat liver proteins and in an internal region of Y44. A number of similarities in the sequences of rat liver and E coli ribosomal proteins have been found; however, it is not yet possible to say whether they connote a common ancestry.
Subject(s)
Liver/analysis , Ribosomal Proteins/analysis , Amino Acid Sequence , Amino Acids/analysis , Animals , Escherichia coli/analysis , Rats , Saccharomyces cerevisiae/analysisABSTRACT
Fourteen proteins from the large subunit of Escherichia coli ribosomes were analyzed in an improved sequenator. In addition to our previously described modifications of a Beckman sequenator, new valves which work free of a dead volume were constructed. By this and the previous improvements (e.g., a new vacuum system with a recorder, cool traps, automatic conversion) much better results were obtained than before. It was even possible to use (in addition to the standard methods, e.g., thin-layer chromatography and amino acid analysis) mass spectrometry without preceding gas chromatography for identification of the released PTH amino acids. Our experience with the various methods, especially mass spectrometry, is described and the techniques are compared. The results obtained by the described methods on the amino acid sequences of the 14 ribosomal proteins are summarized.
