The primary structure of rat ribosomal protein L7. The presence near the amino terminus of L7 of five tandem repeats of a sequence of 12 amino acids

The covalent structure of rat ribosomal protein L7 was determined in part from the sequence of nucleotides in a recombinant cDNA and in part from the sequence of amino acids in portions of the protein. The complementary analyses supplemented and confirmed each other. Ribosomal protein L7 contains 258 amino acids and has a molecular weight of 30,040. The protein has an unusual and striking structural feature near the NH2 terminus: five tandem repeats of a sequence of 12 residues. Rat L7 appears to be related to ribosomal protein L7 from the moderate halophile Vibrio costicola and perhaps to L30 from Bacillus stearothermophilus, to L7 from the moderate halophile NRCC 41227, and to L22 from Nicotinia tobaccum chloroplast. In addition, there is a sequence of 24 amino acids in rat protein L7 that may be related to segments of the same number of residues in Escherichia coli ribosomal proteins S10, S15, L9, and L22.     

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 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 S7

The amino acid sequence of the rat 40S ribosomal subunit protein S7 was deduced from the sequence of nucleotides in two recombinant cDNAs and confirmed from the amino acid sequence of a cyanogen bromide peptide obtained from the protein. Ribosomal protein S7 has 194 amino acids and has a molecular mass of 22,113. Hybridization of the cDNA to digest of nuclear DNA suggests that there are 14-16 copies of the S7 gene. The mRNA for the protein is about 725 nucleotides in length. Rat S7 is homologous with Xenopus laevis S8. The protein contains a possible internal duplication of 10 residues.     

The primary structure of rat ribosomal protein S20

The amino acid sequence of the rat 40 S ribosomal subunit protein S20 was deduced from the sequence of nucleotides in two recombinant cDNAs. Ribosomal protein S20 has 119 amino acids and has a molecular weight of 13,364. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 16-19 copies of the S20 gene. The mRNA for the protein is about 600 nucleotides in length. Rat S20 is homologous to Xenopus laevis S22 and is related to Mycoplasma capricolum S10 and to Escherichia coli S10. The protein contains a possible internal duplication of seven residues.     

Snake venom toxins. The primary structure of protein S4C11. A neurotoxin homologue from the venom of forest cobra (Naja melanoleuca).

Six minor protein constituents (S4C10-S4C15) have been isolated from the venom of Naja melanoleuca. The complete amino acid sequence of S4C11 has been established and indicates that it is a homologue of the neurotoxins which are found in elapid venoms. The other proteins appear from the amino acid compositions to be homologues of the cyto- or cardiotoxins found in cobra venoms. Protein S4C11 has a low toxicity, failing to kill mice at an intravenous dose of 20 mug/g body weight. The sequence of the first 25 residues out of the total of 65, was determined using the automatic sequenator. The remainder of the sequence was derived with the aid of tryptic and chymotryptic peptides. The sequence showed the unusual feature of having 65 amino acid residues including 10 half-cystine residues.     

The core protein of alphaviruses. 1. Purification of peptides and complete amino-acid sequence of Semliki Forest virus core protein

The primary structure of the core protein of Semliki Forest virus has been established by protein chemical characterization of 102 peptides, generated by digestion with trypsin, pepsin, thermolysin, and by partial acid cleavage of the protein. Besides a difference in one position, the sequence as established by these experiments is in agreement with the sequence predicted from the nucleotide sequence of the mRNA [Garoff et al. (1980) Proc. Natl Acad. Sci. USA, 77, 6376-6380]. The core protein has a blocked N terminus, consists of 267 amino acid residues, and has the following amino acid composition: Asp12, Asn9, Thr16, Ser10, Glu11, Gln15, Pro23, Gly20, Ala23, Val19, Met8, Ile11, Leu9, Tyr7, Phe6, His7, Lys37, Arg15, Trp5, Cys4, and an Mr of 29919. It contains 22.1% basic amino acids, mainly lysines, compared with a total of 8.6% acidic residues. The resulting surplus of positive charge is located in the N-terminal half of the protein (predominantly arginines at positions 12-21 and lysines at positions 66-114). Other amino acids are also unevenly distributed; proline and glutamine are accumulated in the N-terminal half of the sequence whereas histidine, glycine and the acidic residues are mainly present in the C-terminal part. This distribution suggests that the virus core protein consists of two or more structural domains.     

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.     

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 L19. A determination from the sequence of nucleotides in a cDNA and from the sequence of amino acids in the protein

The covalent structure of rat ribosomal protein L19 was inferred from the sequence of nucleotides in a recombinant cDNA and confirmed from the sequence of amino acids in a portion of the protein. Ribosomal protein L19 contains 196 amino acids and has a molecular weight of 26,971. There are indications that a segment of 23 residues in rat L19 is related to sequences of the same length in Escherichia coli ribosomal proteins L30, L18, and S2.     

The primary structure of the human ribosomal protein S6 derived from a cloned cDNA

Polyclonal antibodies directed against a synthetic octapeptide of the cAMP-dependent phosphorylation site of the ribosomal protein S6 of rat liver were used to screen a lambda gt11 cDNA expression library of human lymphoblasts. An S6 specific clone was isolated. It consists of the complete coding sequence of 747 base pairs and the 3' noncoding region of 40 base pairs. The sequence of 249 amino acids was deduced from the nucleotide sequence. The amino- and carboxyl-terminal regions are almost identical to the reported partial peptide sequences of rat liver S6. The yeast protein S10 is homologous to the human S6 with the exception of 3 amino acid insertions and a carboxyl-terminal extension of 10 amino acids within the human S6. The only two phosphorylation sites at the carboxyl terminus of yeast S10 are homologous to the two cAMP-dependent sites in human S6. Since there are additional phosphorylation sites in mammalian S6, one can assume that they are located in the cluster of 5 serines within the carboxyl-terminal extension. The sequence comparison of these two ribosomal proteins from evolutionarily distant eucaryotes, such as man and yeast, indicates that the structure and probably the function of the phosphoprotein S6 of the small ribosomal subunit has been highly conserved. The expression of the S6 gene has been investigated in proliferating lymphocytes stimulated by concanavalin A. During all stages of lymphoblast development the level of S6 mRNA appeared to be similar. Southern blot analysis of human genomic DNA suggests that multiple genes exist for the S6 protein.     

Extensive sequence homology between IgA receptor and M proteins in Streptococcus pyogenes

Many strains of Streptococcus pyogenes are known to express a receptor for IgA. The complete nucleotide sequence of the gene for such a receptor, protein Arp4, has been determined. The deduced amino acid sequence of 386 residues includes a signal sequence of 41 amino acids and a putative membrane anchor region, both of which are homologous to similar regions in other streptococcal surface proteins. The processed form of the IgA receptor has a length of 345 amino acids and a calculated molecular weight of 39544. The N-terminal sequence of the processed form is different from that previously found for a similar IgA receptor isolated from a S. pyogenes strain of type M60. The sequence of protein Arp4 shows extensive homology to the C-terminal half of streptococcal M proteins, but not to the streptococcal IgG receptor protein G or staphlyococcal protein A. Apart from the membrane anchor, this homology includes a sequence of 119 amino acid residues containing three repeated units and a 54-residue sequence without repeats. The protein expressed in Escherichia coli is found in the periplasmic space, in which it constitutes the major protein. Protein Arp4 is the first example of a surface protein that has both immunoglobulin-binding capacity and structural features characteristic of M proteins.     

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.     

褐飞虱乙酰胆碱酯酶基因全长cDNA的克隆及序列分析

利用反转录聚合酶链式反应(RT_PCR)结合快速扩增cDNA末端(RACE)技术克隆了褐飞虱Nilaparvata lugens 乙酰胆碱酯酶基因cDNA。该cDNA全长2 467 bp,包含一个1 938 bp的开放阅读框(GenBank登录号AJ852420); 在推导出的646个氨基酸残基的前体蛋白中, N端的前30个氨基酸残基为信号肽,随后的616个氨基酸残基是成熟的乙酰胆碱酯酶序列,其预测的分子量为69 418 D。在一级结构中,形成催化活性中心的3个氨基酸残基(Ser242,Glu371和His485),以及在亚基内形成二硫键的6个半胱氨酸完全保守; 位于催化功能域的14个芳香族氨基酸中有10 个完全保守。该酶的氨基酸序列与黑尾叶蝉的同源性最高,达83%。对来自23种昆虫（包括褐飞虱）的30个乙酰胆碱酯酶的聚类分析显示,褐飞虱的乙酰胆碱酯酶与其中6个Ⅱ型乙酰胆碱酯酶（AChE2）同属一个支系; 此外,只存在于昆虫AChE2中的超变区及特异的氨基酸残基,也存在于褐飞虱的乙酰胆碱酯酶中。以上结果表明,所克隆的褐飞虱的乙酰胆碱酯酶基因是一个与黑腹果蝇的orthologous型基因同源的AChE2基因。     

Cloning and sequence analysis of a cDNA encoding a Brazil nut protein exceptionally rich in methionine

The primary amino acid sequence of an abundant methionine-rich seed protein found in Brazil nut (Bertholletia excelsa H.B.K.) has been elucidated by protein sequencing and from the nucleotide sequence of cDNA clones. The 9 kDa subunit of this protein was found to contain 77 amino acids of which 14 were methionine (18%) and 6 were cysteine (8%). Over half of the methionine residues in this subunit are clustered in two regions of the polypeptide where they are interspersed with arginine residues. In one of these regions, methionine residues account for 5 out of 6 amino acids and four of these methionine residues are contiguous. The sequence data verifies that the Brazil nut sulfur-rich protein is synthesized as a precursor polypeptide that is considerably larger than either of the two subunits of the mature protein. Three proteolytic processing steps by which the encoded polypeptide is sequentially trimmed to the 9 kDa and 3 kDa subunit polypeptides have been correlated with the sequence information. In addition, we have found that the sulfur-rich protein from Brazil nut is homologous in its amino acid sequence to small water-soluble proteins found in two other oilseeds, castor bean (Ricinus communis) and rapeseed (Brassica napus). When the amino acid sequences of these three proteins are aligned to maximize homology, the arrangement of cysteine residues is conserved. However, the two subunits of the Brazil nut protein contain over 19% methionine whereas the homologous proteins from castor bean and rapeseed contain only 2.1% and 2.6% methionine, respectively.     

The DNA sequence of the nuclear gene coding for the 17-kd subunit VI of the yeast ubiquinol-cytochrome c reductase: a protein with an extremely high content of acidic amino acids

We have determined the DNA sequence of the nuclear gene coding for the 17-kd subunit VI of the ubiquinol-cytochrome c reductase. The reading frame found encodes a putative polypeptide of 17 394 daltons. This protein is highly unusual: 38% of its residues are acidic and 14% are basic amino acids. The most notable feature in the protein sequence is a stretch of 25 consecutive acidic amino acids. The polypeptide has homology with the 9-kd so-called 'hinge' protein of beef-heart complex III, which also has a cluster of acidic residues. Acidic amino acids are likely to be essential for the function of these proteins, since their degree of conservation is higher than that of other residues.     

Purification and amino acid sequence of lactocin S, a bacteriocin produced by Lactobacillus sake L45.

Lactocin S, a bacteriocin produced by Lactobacillus sake L45, has been purified to homogeneity by ion exchange, hydrophobic interaction and reverse-phase chromatography, and gel filtration. The purification resulted in approximately a 40,000-fold increase in the specific activity of lactocin S and enabled the determination of a major part of the amino acid sequence. Judging from the amino acid composition, lactocin S contained approximately 33 amino acid residues, of which about 50% were the nonpolar amino acids alanine, valine, and leucine. Amino acids were not detected upon direct N-terminal sequencing, indicating that the N-terminal amino acid was blocked. By cyanogen bromide cleavage at an internal methionine, the sequence of the 25 amino acids (including the methionine at the cleavage site) in the C-terminal part of the molecule was determined. The sequence was Met-Glu-Leu-Leu-Pro-Thr-Ala-Ala-Val-Leu-Tyr-Xaa-Asp-Val-Ala-Gly-Xaa-Phe- Lys-Tyr-Xaa-Ala-Lys-His-His, where Xaa represents unidentified residues. It is likely that the unidentified residues are modified forms of cysteine or amino acids associated with cysteine, since two cysteic acids per lactocin S molecule were found upon performic acid oxidation of lactocin S. The sequence was unique when compared to the SWISS-PROT data bank.