Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Haploid cells of mating type A of the basidiomycetous yeast Rhodosporidium toruloides secrete a mating pheromone, rhodotorucine A, which is an undecapeptide containing S-farnesyl cysteine at its carboxy terminus. To analyze the processing and secretion pathway of rhodotorucine A, we isolated both genomic and complementary DNAs encoding the peptide moiety. We identified three distinct genes, RHA1, RHA2, and RHA3, encoding four, five, and three copies of the pheromone peptide, respectively. Complementary DNA clones were classified into two types. One type was homologous to RHA1, and the other type was homologous to RHA2. Transcription start sites were identified by primer extension and S1 nuclease protection, from which the site of the initiator methionine was verified. A primary precursor of rhodotorucine A was detected as a 7-kilodalton protein by immunoprecipitation of in vitro translation products. On the basis of these results, we propose similar three-precursor structures of rhodotorucine A, each containing the amino-terminal peptide sequence Met-Val-Ala. The precursors contain three, four, or five tandem repeats of the pheromone peptide, each separated by a spacer peptide, Thr-Val-Ser(Ala)-Lys, and each precursor has the carboxy-terminal sequence Thr-Val-Ala. This structure suggests that primary precursors of rhodotorucine A do not contain canonical signal sequences.
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PMID:Multiple genes coding for precursors of rhodotorucine A, a farnesyl peptide mating pheromone of the basidiomycetous yeast Rhodosporidium toruloides. 257 24

A hemolytic assay was developed with the primary aim of being able to identify human lymphocytes producing anti-dsDNA antibodies found in patients with systemic lupus erythematosus (SLE). The coating of sheep red-blood cells with DNA was performed after precoating the cells with poly-L-lysine. The DNA-SRBC were lysed by anti-DNA antibodies from SLE sera, and the percent hemolysis was found to correlate with the anti-DNA activity demonstrated by the Farr assay (r = 0.87). Single-stranded DNA at the surface of the coated cells could be removed after digestion with nuclease S1. The effect of the digestion was verified by SLE serum specific for single-stranded DNA. With slight modifications, the target cells may be used to determine not only the titer of anti-DNA antibodies but also the complement-consumption and immunoglobulin classes of the anti-DNA antibodies.
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PMID:Immune hemolytic assay for identification of human anti-dsDNA antibodies with DNA-coated red blood cells as target cells. 283 17

A cDNA clone, pTU04, which hybridizes to two different sizes of mRNA on Northern blots was isolated from soybean suspension culture cell poly(A) RNA. Northern analysis reveals that meristematic tissue produces a 1050-nucleotide mRNA while quiescent mature cells produce primarily a 1220-nucleotide mRNA homologous to pTU04. The cDNA and its corresponding genomic clone have been partially characterized. The nucleotide sequence of the gene predicts a proline-rich protein, designated SbPRP1, which contains a signal peptide sequence and 43 repeats of a sequence consisting primarily of Pro-Pro-Val-Tyr-Lys (CCA-CCA-GTT-TAC-AAG). From nuclease S1 and hybrid-select translation analyses, the cDNA clone pTU04 appears to represent the mRNA for the mature tissue 1220-nucleotide RNA observed on Northern blots. Although there is no direct proof that the encoded protein is a cell wall protein, it has the properties similar to previously isolated cell wall proteins: 1) it is very basic with a high content of Pro, Tyr, and Lys; 2) it has similar hydropathic properties; and 3) its repeating unit shares sequence homology with that of more highly characterized cell wall proteins, generally termed extensin (Chen, J., and Varner, J. E. (1985) EMBO J. 4, 2145-2151; Smith, J. J., Muldoon, E. P., Willard, J. J., and Lamport, D. T. A. (1986) Phytochemistry 25, 1021-1030.
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PMID:Characterization and sequence analysis of a developmentally regulated putative cell wall protein gene isolated from soybean. 303 11

A 9.7-kilobase pair segment of the Escherichia coli chromosome spanning the hisT and purF loci has been characterized. Six genes were identified in this region by complete DNA sequence analysis, in vivo expression in maxicells, and RNA transcript analysis. S1 nuclease analysis has demonstrated that some of these genes are part of the hisT or purF operons. Two of the newly identified genes, dedA and dedB, were localized immediately downstream of hisT in the hisT operon. Two other genes, denoted dedC and dedD, have been localized between the hisT and purF operons. The other two genes, dedE and dedF flank the purF gene. dedE has been previously described as the first gene in the purF operon (Makaroff, C.A., and Zalkin, H. (1985) J. Biol. Chem. 260, 10378-10387). dedF was localized downstream from purF and is part of the purF operon. In addition, dedF is homologous to the ubiX gene of Salmonella typhimurium. Adjacent to dedF is the E. coli homologue of the S. typhimurium argT locus encoding the lysine/arginine/ornithine-binding protein. All of the genes in this region of the chromosome were found to be transcribed in a counter-clockwise direction on the E. coli map which revises the direction of purF transcription.
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PMID:The hisT-purF region of the Escherichia coli K-12 chromosome. Identification of additional genes of the hisT and purF operons. 304 Jul 34

Pregnancy-specific beta 1-glycoprotein (PS beta G) isolated from human placenta consists of a set of at least three glycoproteins with apparent molecular masses of 72, 64, and 54 kDa, respectively. This heterogeneity is confirmed by the detection of three nonglycosylated polypeptides of 50, 48, and 36 kDa, which can be immunoprecipitated by antiserum to placental PS beta G obtained by in vitro translation of placental poly(A)+ RNA. To examine the structural relationships between these proteins, two cDNA clones of 1912 base pairs (PSG16) and 2131 base pairs (PSG93) encoding human PS beta Gs were isolated from a human placental lambda gt11 cDNA library. The sequenced portions of these two cDNAs are identical with the exception that clone PSG93 contains an additional 86 base pairs at the end of the common 3'-coding region. This insertion could result in the generation of a PS beta G species of 419 amino acid residues instead of the 417 amino acid residues predicted by the sequence of clone PSG16. The calculated molecular masses of the two polypeptides encoded by PSG16 and PSG93 are 46.9 and 47.2 kDa, close to the size of the major nonglycosylated PS beta G of 48 kDa. The identity of proteins coded for by these cDNA clones was confirmed by comparing the predicted amino acid sequences to sequences determined from endoproteinase Lys-C peptides obtained from human placental PS beta G. Two placental PS beta G mRNAs of 2200 bases (major) and 1700 bases (minor) have been detected by Northern hybridization analysis. Primer extension and S1 nuclease mapping experiments demonstrated that PS beta G mRNAs have heterogeneous 5' termini.
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PMID:Isolation and characterization of complementary DNAs encoding human pregnancy-specific beta 1-glycoprotein. 325 88

We determined the complete nucleotide sequence of the RAD3 gene of Saccharomyces cerevisiae. The coding region of the gene contained 2,334 base pairs that could encode a protein with a calculated molecular weight of 89,796. Analysis of RAD3 mRNA by Northern blots and by S1 nuclease mapping indicated that the transcript was approximately 2.5 kilobases and did not contain intervening sequences. Fusions between the RAD3 gene and the lac'Z gene of Escherichia coli were constructed and used to demonstrate that the RAD3 gene was not inducible by DNA damage caused by UV radiation or 4-nitroquinoline-1-oxide. Two UV-sensitive chromosomal mutant alleles of RAD3, rad3-1 and rad3-2, were rescued by gap repair of a centromeric plasmid, and their sequences were determined. The rad3-1 mutation changed a glutamic acid to lysine, and the rad3-2 mutation changed a glycine to arginine. Previous studies have shown that disruption of the RAD3 gene results in loss of an essential function and is associated with inviability of haploid cells. In the present experiments, plasmids carrying the rad3-1 and rad3-2 mutations were introduced into haploid cells containing a disrupted RAD3 gene. These plasmids expressed the essential function of RAD3 but not its DNA repair function. A 74-base-pair deletion at the 3' end of the RAD3 coding region or a fusion of this deletion to the E. coli lac'Z gene did not affect either function of RAD3.
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PMID:RAD3 gene of Saccharomyces cerevisiae: nucleotide sequence of wild-type and mutant alleles, transcript mapping, and aspects of gene regulation. 388 9

The nucleotide sequence of the yeast gene TRP5 and its 5' and 3' flanking regions was determined. The deduced coding sequence for tryptophan synthase contains 2,127 base pairs. The protein chain has a calculated molecular weight of 76,544. Yeast tryptophan synthase, a bifunctional protein, has a primary structure which corresponds to an Escherichia coli tryptophan synthase alpha chain-beta chain fusion. An NH2-terminal 239 amino acid segment of yeast tryptophan synthase is homologous with E. coli tryptophan synthase alpha subunit, while a distal 389 amino acid residue segment is homologous to the E. coli tryptophan synthase beta chain. This order of segments of the yeast enzyme is the reverse of the chromosomal order characteristic of all prokaryotes that have been examined. The two segments are joined by a connecting region of 28 residues in the yeast enzyme which is not homologous to either the alpha or beta chains of the bacterial enzyme. A portion of the connecting region of yeast tryptophan synthase exhibits nucleotide sequence similarity to the 3' terminus of E. coli trpC and the trpC-trpB intercistronic region. Active site cysteine, histidine, and lysine residues in the beta 2 subunit of E. coli tryptophan synthase are conserved in the yeast enzyme. Also conserved in the yeast enzyme are 6/8 amino acid residues having an important role in maintaining the structure and function of the E. coli tryptophan synthase alpha subunit. S1 nuclease mapping was used to identify three major mRNA transcripts with different 5' termini. Potential T-A-T-A sites for transcription initiation were identified, as well as other sequences that occur frequently in yeast genes. A 5' flanking region of TRP5 was shown by DNA/DNA hybridization to be present in multiple copies in the yeast genome. TRP5 mRNA levels, measured by RNA/DNA hybridization, increased 2- to 7-fold in response to starvation for either tryptophan or histidine, indicating transcriptional regulation.
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PMID:Yeast gene TRP5: structure, function, regulation. 627 87

Modification with acetic anhydride of nucleosomes from chicken erythrocytes at low ionic strength (less than 0.1 M NaCl) is accompanied by the formation of residual particles and the release of free DNA. This DNA has been identified as single-stranded by thermal denaturation, digestion with nuclease S1, and elution from hydroxyapatite. In contrast, if modification takes place at 0.6 M NaCl, the liberated DNA is mainly double-stranded. The release of the free energy stored in folded nucleosomal DNA, triggered by the weakening of lysine-DNA interactions which takes place upon modification, might be responsible for the observed denaturation of DNA at low ionic strength.
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PMID:Dissociation of single-stranded DNA from nucleosomes following modification with acetic anhydride. 674 21

A sensitive solid phase microradioimmunoassay has been developed for measurement of antidouble stranded DNA (dsDNA) antibodies. In this procedure, advantage has been taken of the capacity of poly-L-lysine (PLL) to facilitate the binding of pure dsDNA to plastic surfaces. In the absence of PLL, binding did not occur. Diluted sera were incubated in PLL-treated dsDNA-coated microtitration trays and anti-dsDNA Ig measured using affinity purified 125I-anti-Ig of high specific activity. The synthetic DNA, poly dA-dT, was used as a model for dsDNA. In initial experiments, specific anti-DNA binding could not be demonstrated because of high background binding of patient Ig to PLL-treated surfaces. This was reduced by diluting test sera and anti-Ig in buffer containing 2% BGG and 1% BSA. Specificity of the assay for DNA was demonstrated by absorbing the anti-DNA activity on DNA-coated plastic. The binding of systemic lupus erythematosus (SLE) patient serum Ig to poly dA-dT coated trays did not diminish after digestion with nuclease S1, suggesting that the synthetic polymer is an appropriate model for dsDNA. Patient and normal sera were screened for anti-dsDNA activity using poly dA-dT as antigen. None of the 38 normal sera, 23 of 35 active SLE sera, 1 of 25 treated SLE, 4 of 35 rheumatoid arthritis, 3 of 35 scleroderma, and 1 of 13 polymyositis sera demonstrated positive anti-dsDNA activity. The anti-dsDNA values obtained in the radioimmunoassay correlated significantly with those obtained in the Crithidia luciliae assay.
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PMID:A sensitive solid phase microradioimmunoassay for anti-double stranded DNA antibodies. 697 Nov 3

Two promoters required for expression of the ask-asd genes, encoding aspartokinase (AK) and aspartate-semialdehyde dehydrogenase (ASD), in Corynebacterium flavum N13, askP1 and askP2, have been identified by deletion analysis and S1 nuclease mapping. Transcription from askP1 initiates 35 and 38 bp upstream of the ask structural gene. A second promoter, askP2, lies within the ask coding region, upstream of the translation start site of the AK beta subunit and can direct the expression of AK beta and ASD. Western immunoblot analysis and heterologous expression in Escherichia coli demonstrate that two separate polypeptides, a 44.8-kDa alpha subunit and an 18.5-kDa beta subunit, are expressed from the C. flavum N13 ask gene from distinct, in-frame translation initiation sites. A second AK mutation, G345D, which reduces the sensitivity of AK to concerted feedback inhibition by threonine plus lysine, was identified.
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PMID:Gene structure and expression of the Corynebacterium flavum N13 ask-asd operon. 810 May 67


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