The primary structure of rat ribosomal protein L37a

The amino acid sequence of rat ribosomal protein L37a was deduced from the sequence of nucleotides in recombinant cDNAs isolated in Yamagata and in Chicago and confirmed from the NH2-terminal amino acid sequence of the protein. Ribosomal protein L37a contains 91 amino acids (the NH2-terminal methionine is removed after translation of the mRNA) and has a molecular mass of 10143 Da.     

The primary structure of chicken ribosomal protein L5.

The nucleotide sequence of a cDNA for chicken ribosomal protein L5, which is considered to associate with 5S rRNA, was determined. The cDNA is 975 bp long. The deduced protein has 297 amino acids and has a molecular mass of 34,090 Da. A comparative analysis of the amino acid sequences of chicken L5 and its homologous proteins revealed an extremely conserved region which contains a cluster of basic amino acids.     

The primary structure of rat liver ribosomal protein L37. Homology with yeast and bacterial ribosomal proteins

The covalent structure of the rat liver 60 S ribosomal subunit protein L37 was determined. Twenty-four tryptic peptides were purified and the sequence of each was established; they accounted for all 111 residues of L37. The sequence of the first 30 residues of L37, obtained previously by automated Edman degradation of the intact protein, provided the alignment of the first 9 tryptic peptides. Three peptides (CN1, CN2, and CN3) were produced by cleavage of protein L37 with cyanogen bromide. The sequence of CN1 (65 residues) was established from the sequence of secondary peptides resulting from cleavage with trypsin and chymotrypsin. The sequence of CN1 in turn served to order tryptic peptides 1 through 14. The sequence of CN2 (15 residues) was determined entirely by a micromanual procedure and allowed the alignment of tryptic peptides 14 through 18. The sequence of the NH2-terminal 28 amino acids of CN3 (31 residues) was determined; in addition the complete sequences of the secondary tryptic and chymotryptic peptides were done. The sequence of CN3 provided the order of tryptic peptides 18 through 24. Thus the sequence of the three cyanogen bromide peptides also accounted for the 111 residues of protein L37. The carboxyl-terminal amino acids were identified after carboxypeptidase A treatment. There is a disulfide bridge between half-cystinyl residues at positions 40 and 69. Rat liver ribosomal protein L37 is homologous with yeast YP55 and with Escherichia coli L34. Moreover, there is a segment of 17 residues in rat L37 that occurs, albeit with modifications, in yeast YP55 and in E. coli S4, L20, and L34.     

The primary structure of rat ribosomal protein L8.

The amino acid sequence of the rat 60S ribosomal subunit protein L8 was deduced from the sequence of nucleotides in a recombinant cDNA. Ribosomal protein L8 has 257 amino acids and has a molecular weight of 28,007. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 4 or 5 copies of the L8 gene. The mRNA for the protein is about 950 nucleotides in length. Rat L8 is homologous to ribosomal proteins from other eukaryotes and to proteins from eubacterial, archaebacterial, and chloroplast ribosomes.     

The primary structure of rat ribosomal protein L23.

The amino acid sequence of the rat 60S ribosomal subunit protein L23 was deduced from the sequence of nucleotides in two recombinant cDNAs. Ribosomal protein L23 has 140 amino acids and a molecular weight of 14,856. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 7-9 copies of the L23 gene. The mRNA for the protein is about 600 nucleotides in length. Rat L23 is homologous to Saccharomyces cerevisiae L17a and related to Escherichia coli L14 and other members of the prokaryotic L14 family.     

The primary structure of rat ribosomal protein L38.

The amino acid sequence of the rat 60S ribosomal protein L38 was deduced from the sequence of nucleotides in three recombinant cDNAs. Ribosomal protein L38 has 69 amino acids (the NH2-terminal methionine is removed after translation of the mRNA) and has a molecular weight of 8,081. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 11-13 copies of the L38 gene. The mRNA for the protein is about 450 nucleotides in length.     

The primary structure of rat ribosomal protein L3.

The amino acid sequence of the rat 60S ribosomal subunit protein L3 was deduced from the sequence of nucleotides in a recombinant cDNA. Ribosomal protein L3 has 403 amino acids and has a molecular weight of 46,106. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 7 to 9 copies of the L3 gene. The mRNA for the protein is about 1,400 nucleotides in length. Rat L3 is homologous to ribosomal proteins from other eukaryotes and to proteins from eubacterial, archaebacterial, and chloroplast ribosomes.     

The primary structure of rat ribosomal protein L18a

The amino acid sequence of rat ribosomal protein L18a was deduced from the sequence of nucleotides in a recombinant cDNA. Ribosomal protein L18a contains 175 amino acids and has a molecular mass of 20,047 Da. Hybridization of the cDNA to digests of rat nuclear DNA and to a preparation of poly(A)+ mRNA suggests that there are 8-11 copies of the L18a gene and that the mRNA for the protein is about 700 nucleotides in length. Rat L18a is related to Schizosaccharomyces pombe L17 and perhaps to Halobacterium marismortui L19.     

The primary structure of rat ribosomal protein L35

The amino acid sequence of the rat 60S ribosomal subunit protein L35 was deduced from the sequence of nucleotides in a recombinant cDNA and confirmed from the NH2-terminal amino acid sequence of the protein. Ribosomal protein L35 has 122 amino acids (the NH2-terminal methionine is removed after translation of the mRNA) and has a molecular weight of 14,412. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 15-17 copies of the L35 gene. The mRNA for the protein is about 570 nucleotides in length. Rat L35 is related to the archaebacterial ribosomal proteins Halobacterium marismortui L33 and Halobacterium halobium L29E; it is also related to Escherichia coli L29 and to other members of the prokaryotic ribosomal protein L29 family. The protein contains a possible internal duplication of 11 residues.     

The primary structure of rat ribosomal protein L9

The amino acid (aa) sequence of rat ribosomal (r) protein L9 was deduced from the nucleotide (nt) sequence in a recombinant cDNA and confirmed from the N-terminal aa sequence of the protein. L9 contains 192 aa and has an Mr of 21879. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 20-23 copies of the L9 gene. The mRNA for the protein is about 800 nt in length. Rat L9 is related to Saccharomyces cerevisiae YL11, Methanococcus vannielii L6, Escherichia coli L6 and other members of the prokaryotic L6 family. The protein contains a possible internal duplication of 11 aa.     

The primary structure of rat ribosomal protein L21

The covalent structure of rat ribosomal protein L21 was deduced from the sequence of nucleotides in a recombinant cDNA and confirmed from the NH2-terminal amino acid sequence of the protein. Ribosomal protein L21 contains 159 amino acids (the NH2-terminal methionine is removed after translation of the mRNA) and has a molecular weight of 18,322. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 16-23 copies of the L21 gene. The mRNA for the protein is about 680 nucleotides in length.     

The primary structure of rat ribosomal protein L17

The amino acid sequence of the rat 60S ribosomal subunit protein L17 was deduced from the sequence of nucleotides in two recombinant cDNAs. Ribosomal protein L17 has 184 amino acids and has a molecular weight of 21,383. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 17-19 copies of the L17 gene. The mRNA for the protein is about 720 nucleotides in length. Rat L17 is homologous to human L17 and related to Saccharomyces cerevisiae YL17, Halobacterium marismortui L23, Halobacterium halobium L22e, Escherichia coli L22 and other members of the prokaryotic L22 family.     

The primary structure of rat ribosomal protein L12

The covalent structure of the rat 60S subunit protein L12 which is a component of the ribosomal elongation factor binding domain was deduced from the sequence of nucleotides in a recombinant cDNA and confirmed from the NH2-terminal amino acid sequence of the protein. L12 has 165 amino acids and a molecular weight of 17,834. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 11-13 copies of the L12 gene. The mRNA for the protein is about 800 nucleotides in length. Rat L12 is homologous to Saccharomyces cerevisiae L15. The cDNA contains the highly repetitive DNA sequence, R.dre.1, in the 3' noncoding region.     

The primary structure of rat ribosomal protein L26

The amino acid sequence of rat ribosomal protein L26 was deduced from the sequence of nucleotides in a recombinant cDNA and confirmed from the NH2-terminal amino acid sequence of the protein. Rat L26 contains 145 amino acids and has a molecular mass of 17,266 Da. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 8-16 copies of the L26 gene. The mRNA for the protein is about 650 nucleotides in length. Protein L26 has a sequence of 9 residues that may be repeated in three places.     

The primary structure of rat liver ribosomal protein L39

The covalent structure of the rat liver 60 S ribosomal subunit protein L39 was determined. Fourteen tryptic peptides were purified, and the sequence of each was established by a micromanual procedure; they accounted for all 50 residues of L39. The sequence of the NH2-terminal 32 residues of L39, obtained by automated Edman degradation of the intact protein, provided the alignment of the first seven tryptic peptides. Two peptides, CNI (28 residues) and CNII (22 residues), were produced by cleavage of protein L39 with cyanogen bromide and the sequence of CNII was determined by automated Edman degradation. This sequence established the order of tryptic peptides T8 through T14. The carboxyl-terminal amino acids were identified after carboxypeptidase A treatment. Protein L39 contains 50 amino acids and has a molecular weight of 7308. There are indications that a portion of rat L39 is related to a fragment of Escherichia coli ribosomal protein S1.     

The complete primary structure of ribosomal protein L1 fromThermus thermophilus

The primary structure of the 23S rRNA binding ribosomal protein L1 from the 50S ribosomal subunit ofThermus thermophilus ribosomes has been elucidated by direct protein sequencing of selected peptides prepared by enzymatic and chemical cleavage of the intact purified protein. The polypeptide chain contains 228 amino acids and has a calculated molecular mass of 24,694 D. A comparison with the primary structures of the corresponding proteins fromEscherichia coli andBacillus stearothermophilus reveals a sequence homology of 49% and 58%, respectively. With respect to both proteins, L1 fromT. thermophilus contains particularly less Ala, Lys, Gln, and Val, whereas its content of Glu, Gly, His, Ile, and Arg is higher. In addition, two fragments obtained by limited proteolysis of the intact, unmodified protein were characterized.