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 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 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 S19

The covalent structure of rat ribosomal protein S19 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 S19 contains 144 amino acids (the NH2-terminal methionine is removed after translation of the mRNA) and has a molecular weight of 15,944. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 15-18 copies of the S19 gene. The mRNA for the protein is about 640 nucleotides in length. Rat S19 is related to Saccharomyces cerevisiae S16A and to Halobacterium marismortui S12.     

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 proteins: the amino acid sequences of L27a and L28 and corrections in the sequences of S4 and S12

The amino acid sequences of rat ribosomal proteins L27a and L28 were deduced from the sequences of nucleotides in recombinant cDNAs and confirmed from the NH2-terminal amino acid sequences of the proteins. L27a contains 147 amino acids (the NH2-terminal methionine is removed after translation of the mRNA) and has a molecular weight of 16 476. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 18-22 copies of the L27a gene. The mRNA for the protein is about 600 nucleotides in length. L27a is homologous to mouse L27a (there are 3 amino acid changes) and to yeast L29. Rat ribosomal protein L28 has 136 amino acids (its NH2-terminal methionine is also processed after translation) and has a molecular weight of 15 707. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 9 or 10 copies of the L28 gene. The mRNA for the protein is about 640 nucleotides in length. L28 contains a possible internal duplication of 9 residues. Corrections are recorded in the sequences reported before for rat ribosomal proteins S4 and S12.     

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.     

Molecular cloning and primary structure of rat thyroxine-binding globulin

Rat thyroxine-binding globulin (TBG) cDNAs were isolated from a rat liver cDNA library by using a human TBG cDNA as a probe. From two overlapping cDNA inserts, an aligned cDNA sequence of 1714 nucleotides was obtained. There was 70% homology with human TBG cDNA over the span of 1526 nucleotides. In order to confirm that the cloned cDNA encodes rat TBG and to localize the NH2-terminal amino acid of the mature molecule, the protein was purified by affinity chromatography and subjected to direct protein microsequencing. The NH2-terminal amino acid sequence was identical with that deduced from the nucleotide sequence. The rat TBG cDNA sequenced consisted of a truncated leader sequence (35 nucleotides), the complete sequence encoding the mature protein (1194 nucleotides) and the 3'-untranslated region (485 nucleotides), containing two polyadenylation signals. It was deduced that rat TBG consists of 398 amino acids (Mr = 44,607), three NH2-terminal residues more than human TBG, with which it shares 76% homology in primary structure. Of the six potential N-glycosylation sites, four are located in conserved positions compared to human TBG. Northern blot analysis of rat liver revealed an approximately 1.8-kilobase TBG mRNA. Its amount increased markedly following thyroidectomy and decreased with thyroxine treatment in a dose-dependent manner.     

The primary structure of rat ribosomal protein S13

The covalent structure of the rat 40S ribosomal subunit protein S13 was deduced from the sequence of nucleotides in a recombinant cDNA and confirmed from the NH2-terminal amino acid sequence of the protein. Rat S13 contains 150 amino acids (the NH2-terminal methionine is removed after translation of the mRNA) and has a molecular weight of 17,080. Hybridization of a S13 cDNA to digests of nuclear DNA suggests that there are 8-10 copies of the gene for the protein. The mRNA for the protein is about 620 nucleotides in length. Rat S13 is related to Saccharomyces cerevisiae YS15 and to Halobacterium marismortui S11. The protein contains a possible internal duplication of 12 residues.     

The primary structure of rat ribosomal protein S10

The amino acid sequence of rat ribosomal protein S10 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 S10 contains 165 amino acids and has a molecular mass of 18917 Da. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 17-20 copies of the S10 gene. The mRNA for the protein is about 750 nucleotides in length. Ribosomal protein S10 has several possible internal duplications; one is a tandem repeat of ten residues that is basic and contains two or three prolines.     

The primary structure of rat ribosomal protein S8.

The amino acid sequence of rat ribosomal protein S8 was deduced from the sequence of nucleotides in a recombinant cDNA and confirmed from the NH2- and carboxyl-terminal amino acid sequences of the protein. Ribosomal protein S8 contains 207 amino acids (the NH2-terminal methionine is removed after translation of the mRNA) and has a molecular weight of 23,928. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 7-9 copies of the S8 gene. Ribosomal protein S8 contains a possible internal repeat that has 12 or 13 residues, is basic, and occurs 5 times in the protein.     

Nucleotide sequence of rat alpha 1-acid glycoprotein messenger RNA

The complete nucleotide sequence of rat alpha 1-acid glycoprotein (alpha 1-AGP) mRNA has been determined from cloned double-stranded cDNA. The coding portion of the mRNA was bounded at the ends by a 5'-untranslated region of 35 nucleotides in length and a 3'-untranslated region of 119 nucleotides in length. The 3'-untranslated region contains the characteristic AAUAAA sequence ending 18 nucleotides from the 3'-terminal poly(A) segment. The 5'-region of the mRNA contains two in-phase AUG codons separated by 12 nucleotides. Comparison with the known NH2-terminal amino acid sequence of serum rat alpha 1-AGP suggests that the primary translation product of the mRNA contains an additional 14 or 18 amino acids that are not present in the mature form of the protein, which contains 187 amino acids. The inferred amino acid sequence of rat alpha 1-AGP and the known amino acid sequence of human alpha 1-AGP have several regions of identity clustered in the NH2-terminal portion of the proteins. The carboxyl-terminal regions show significantly less homology. Six potential asparagine glycosylation sites are found in the rat sequence, and four of these sites are in positions similar to known glycosylation sites in the human protein. Furthermore, three of these potential glycosylation sites are in a region that exhibits extensive amino acid sequence conservation, suggesting that this region may be important for the biological function of alpha 1-AGP.     

Rat apolipoprotein E mRNA. Cloning and sequencing of double-stranded cDNA

A 900-base pair clone corresponding to rat liver apolipoprotein E (apo-E) mRNA, and containing a 3'-terminal poly(A) segment, was identified from a library of rat liver cDNA clones in the plasmid pBR322 by specific hybrid selection and translation of mRNA. A restriction endonuclease DNA fragment from this recombinant plasmid was used to clone the 5'-terminal region of the apo-E mRNA by primed synthesis of cDNA. A portion of the double-stranded cDNA corresponding to the 3'-terminal region of apo-E mRNA was subcloned into the bacteriophage M13mp7 and employed as a template for the synthesis of a radioactively labeled, cDNA hybridization probe. This cDNA probe was used in a RNA-blot hybridization assay that showed the length of the apo-E mRNA to be about 1200 nucleotides. The hybridization assay also demonstrated that apo-E mRNA is present in rat intestine, but at about a 100-fold lower level than that of the rat liver. The nucleotide sequence of rat liver apo-E mRNA was determined from the cloned, double-stranded cDNAs. The amino acid sequence of rat liver apo-E was inferred from the nucleotide sequence, which showed that the mRNA codes for a precursor protein of 311 amino acids. A comparison to the NH2-terminal amino acid sequence of rat plasma apo-E indicated that the first 18 amino acids of the primary translation product are not present in the mature protein and are probably removed during co-translational processing. The coding region was flanked by a 3'-untranslated region of 109 nucleotides, which contained a characteristic AAUAAA sequence that ended 13 nucleotides from a 3'-terminal poly(A) segment. At the 5'-terminal region of the mRNA, 23 nucleotides of an untranslated region were also determined. The inferred amino acid sequence of mature rat apo-E, which contains 293 amino acids, was compared to the amino acid sequence of human apo-E, which contains 299 amino acids. Using an alignment that permitted a maximum homology of amino acids, it was found that overall, 69% of the amino acid positions are identical in both proteins. The amino acid identities are clustered in two broad domains separated by a short region of nonhomology, an NH2-terminal domain of 173 residues where 80% are identical, and a COOH-terminal domain of 84 residues where 70% are identical. These two domains may be associated with specific functional roles in the protein.     

The sequence of a cloned cDNA for the beta subunit of bovine thyrotropin predicts a protein containing both NH2-and COOH-terminal extensions

Cloned cDNAs containing sequences coding for the beta subunit of bovine thyrotropin have been identified. The complete nucleotide sequence of the largest of the beta subunit cDNA inserts has been determined. This cDNA contains 35 nucleotides from the 5' untranslated region of thyrotropin beta subunit mRNA and 60 nucleotides coding for an NH2-terminal precursor segment. This is followed by 339 nucleotides which code for the published amino acid sequence of the thyrotropin beta subunit. Following the 339 nucleotide beta subunit coding sequence, no termination codon is encountered for another 15 nucleotides. Thus, the cDNA codes for a thyrotropin beta subunit containing an additional 5 amino acids at the COOH terminus. The cDNA also contains 82 nucleotides of 3' untranslated sequence followed by a short poly(A) segment. Comparison of the bovine cDNA sequence to the recently described mouse thyrotropin beta subunit cDNA sequence reveals considerable homology throughout the coding sequence, including the COOH-terminal extension. These findings suggest the possibility that a thyrotropin beta subunit precursor is processed at both the NH2 and COOH termini.     

The primary structure of rat ribosomal protein S5. A ribosomal protein present in the rat genome in a single copy.

The amino acid sequence of the rat 40 S ribosomal subunit protein S5 was deduced from the sequence of nucleotides in a recombinant cDNA and confirmed by the determination, directly from the protein, of 17 residues near the NH2 terminus. S5 has 204 amino acids; the molecular weight is 22,863. The protein designated S5a has the same amino acid sequence as S5 except that it lacks the NH2-terminal 5 residues. It is not known whether the conversion of a portion of S5 to S5a is physiological or fortuitous. The mRNA for S5 has about 820 nucleotides. Hybridization of the S5 cDNA to digests of nuclear DNA indicates that the rat genome has only a single copy of the gene; this is in distinction to the mouse and human genomes which have three to six copies of the S5 gene. Rat ribosomal protein S5 is related to the eubacteria, the arachaebacteria, and the chloroplast family of S7 ribosomal proteins. There is a peptide of 16 residues at the carboxyl terminus of S5 that is highly conserved in 18 species spanning the three kingdoms and chloroplasts.     

Human microsomal xenobiotic epoxide hydrolase. Complementary DNA sequence, complementary DNA-directed expression in COS-1 cells, and chromosomal localization

A lambda gt11 expression library constructed from human liver mRNA was screened with an antibody against human microsomal xenobiotic epoxide hydrolase. The clone pheh32 contains an insert of 1742 base pairs with an open reading frame coding for a protein of 455 amino acids with a calculated Mr of 52,956. The nucleotide sequence is 77% similar to the previously reported rat xenobiotic epoxide hydrolase cDNA sequence. The deduced amino acid sequence of the human epoxide hydrolase is 80% similar to the previously reported rabbit and 84% similar to the deduced rat protein sequence. The NH2-terminal amino acids deduced from the human xenobiotic epoxide hydrolase cDNA are identical to the published 19 NH2-terminal amino acids of the purified human xenobiotic epoxide hydrolase protein. Northern blot analysis revealed a single mRNA band of 1.8 kilobases. Southern blot analysis indicated that there is only one gene copy/haploid genome. The human xenobiotic epoxide hydrolase gene was assigned to the long arm of human chromosome 1. Several restriction fragment length polymorphisms were observed with the human epoxide hydrolase cDNA. pheh32 was expressed as enzymatically active protein in cultured monkey kidney cells (COS-1).     

Glycinin A3B4 mRNA. Cloning and sequencing of double-stranded cDNA complementary to a soybean storage protein

The cDNA clones encoding the precursor form of glycinin A3B4 subunit have been identified from a library of soybean cotyledonary cDNA clones in the plasmid pBR322 by a combination of differential colony hybridizations, and then by immunoprecipitation of hybrid-selected translation product with A3-mono-specific antiserum. A recombinant plasmid, designated pGA3B41425, from one of six clones covering codons for the NH2-terminal region of the subunit was sequenced, and the amino acid sequence was inferred from the nucleotide sequence, which showed that the mRNA codes for a precursor protein of 516 amino acids. Analysis of this cDNA also showed that it contained 1786 nucleotides of mRNA sequence with a 5'-terminal nontranslated region of 46 nucleotides, a signal peptide region corresponding to 24 amino acids, an A3 acidic subunit region corresponding to 320 amino acids followed by a B4 basic subunit region corresponding to 172 amino acids, and a 3'-terminal nontranslated region of 192 nucleotides, which contained two characteristic AAUAAA sequences that ended 110 nucleotides and 26 nucleotides from a 3'-terminal poly(A) segment, respectively. Our results confirm that glycinin is synthesized as precursor polypeptides which undergo post-translational processing to form the nonrandom polypeptide pairs via disulfide bonds. The inferred amino acid sequence of the mature basic subunit, B4, was compared to that of the basic subunit of pea legumin, Leg Beta, which contained 185 amino acids. Using an alignment that permitted a maximum homology of amino acids, it was found that overall 42% of the amino acid positions are identical in both proteins. These results led us to conclude that both storage proteins have a common ancestor.     

Cloning and sequence analysis of a rat liver cDNA encoding acyl-peptide hydrolase

Acyl-peptide hydrolase catalyzes the removal of an N alpha-acetylated amino acid residue from an N alpha-acetylated peptide. Two overlapping degenerate oligonucleotide probes based on the sequence of a CNBr tryptic peptide, derived from purified rat acyl-peptide hydrolase, were synthesized and used to screen a rat liver lambda gt11 cDNA library. A 2.5-kilobase cDNA was cloned and sequenced. This clone contained 2364 base pairs of rat acyl-peptide hydrolase sequence but lacked a translational initiation codon. Using a 220-base pair probe derived from near the 5'-end of this almost full-length cDNA to rescreen the library, full-length clones were isolated, which contained an in-frame ATG codon at nucleotides 6-8 and encoded the NH2-terminal sequence, Met-Glu-Arg-Gln.... The DNA sequence encoded a protein of 732 amino acid residues, 40% of which were confirmed by protein sequence data from 19 CNBr or CNBr tryptic peptides. The isolated enzyme is NH2-terminally blocked (Kobayashi, K., and Smith, J. A. (1987) J. Biol. Chem. 262, 11435-11445), and based on the NH2-terminal protein sequence deduced from the DNA sequence and the sequence of the most NH2-terminal CNBr peptide, it is likely that the NH2-terminal residue is an acetylated methionine residue, since such residues are frequently juxtaposed to glutamyl residues (Persson, B., Flinta, C., von Heijne, G., and Jornvall, H. (1985) Eur. J. Biochem. 152, 523-527). The RNA blot analysis revealed a single message of 2.7 kilobases in various rat tissues examined. Although this enzyme is known to be inhibited by diisopropyl fluorophosphate and acetylalanine chloromethyl ketone (Kobayashi, K., and Smith, J. A. (1987) J. Biol. Chem. 262, 11435-11445), no strong similarity in protein sequence has been found with other serine proteases. This result suggests that acyl-peptide hydrolase may be a unique serine protease.     

The nucleotide sequence of myosin light chain (L-2A) mRNA from embryonic chicken cardiac muscle tissue.

The nucleotide sequence of a cDNA clone (pML10) for chicken cardiac myosin light chain is described. The cDNA insert contains 613 nucleotides representing the entire coding sequence, with the exception of nine NH2-terminal amino acids, and the full 3'-non-coding region of 146 nucleotides. The missing 5' terminus of the mRNA, not represented in the clone pML10, was obtained by extension of the cDNA using a 43 nucleotide long internal EcoR1 fragment as a primer. The non-coding region contains several direct and inverted repeated sequences and the polyadenylation signal sequence AATAAA. The coding portion exhibits non-random usage of synonymous codons with a strong bias for codons ending in G and C.