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)

I report on the isolation, structural analysis, and in vivo expression patterns of a fungal calmodulin gene. The gene is intronless and encodes a protein of 148 amino acid residues that is 92% homologous with vertebrate calmodulins. Through S1 nuclease transcript mapping, it was determined that the cloned gene (a) is transcribed in vivo, (b) has a 5'-untranslated region of about 400 nucleotides, and (c) has a 3'-untranslated end of about 300 nucleotides. Southern blot hybridization analysis of the genomic DNA and the cloned gene provide evidence for the existence of only one type of calmodulin gene in the organism. The amino acid sequence deduced from the DNA sequence shows that Achlya klebsiana calmodulin has amino acid substitutions that are a mix of those seen in calmodulins from invertebrates such as Drosophila and trypanosome when compared to mammalian calmodulins. Not surprisingly, it has less resemblance to calmodulins from Saccharomyces and Dictyostelium.
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PMID:Structure and expression of fungal calmodulin gene. 280 29

A cDNA clone, SMHC-29, encoding the light meromyosin of smooth muscle myosin heavy chain (MHC), was isolated from a rabbit uterus cDNA library constructed in phage lambda gt11. This smooth muscle MHC cDNA demonstrates significant nucleotide and amino acid sequence homologies with known sarcomeric MHC genes from rabbit, rat skeletal, and nematode body wall myosin, and even with nonmuscle MHC gene from a slime mold (Dictyostelium discoideum), suggesting that smooth muscle, striated muscle, and nonmuscle MHC genes diverged from a common ancestor. The deduced amino acid sequences of the smooth muscle light meromyosin show very similar periodic distributions of hydrophobic and charged residues as found for the light meromyosin of striated muscle MHCs together with a high potential for alpha-helical formation, indicating an alpha-helical coiled-coil structure for the smooth muscle light meromyosin sequences. Furthermore, S1 nuclease mapping has revealed that this smooth muscle MHC gene for SMHC-29 is specifically expressed in smooth muscles of vascular and nonvascular types but not in the striated muscles or nonmuscle cells.
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PMID:Characterization of a mammalian smooth muscle myosin heavy chain cDNA clone and its expression in various smooth muscle types. 342 77

The nucleotide sequence has been determined of a 12,368 base-pair region of DNA cloned from the non-sulphur photosynthetic bacterium Rhodopseudomonas blastica. It contains a cluster of six genes of which five encode the subunits of F1-ATPase; the sixth codes for an unknown protein. The genes are arranged in the same order as in the Escherichia coli unc operon, except that the unknown gene is placed between those for gamma and beta subunits. Neither the genes for F0 subunits, nor a homologue of the E. coli uncI gene is associated with this locus. The six genes are transcribed from a single promoter and we have designated this region the R. blastica atp operon. The two distal genes, beta and epsilon, may also be transcribed from a second promoter. Initiation and termination points for transcription have been identified by primer extensions and S1 nuclease mapping experiments. Signals involved in initiation of translation (Shine and Dalgarno sequences) and termination of transcription in the photosynthetic bacterium resemble those in E. coli. However, no common features can be identified in these two bacteria between 5' regions adjacent to sites of initiation of transcription. The sequence also contains a gene that encodes a protein homologous to discoidin, a cell surface lectin of Dictyostelium discoideum thought to be involved in cell--cell aggregation. Seven other reading frames have not been identified.
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PMID:Rhodopseudomonas blastica atp operon. Nucleotide sequence and transcription. 620 4

The 5S rRNAs from Bombyx mori and Dictyostelium discoideum were end-labeled with [32-P] at either the 5' or 3' end and sequenced using enzymatic digestion. The secondary structure of these molecules was studied using the single-strand specific S1 nuclease and the base-pair specific cobra venom ribonuclease. Computer analysis of these results was performed and was used to generate a consensus secondary structure for each molecule. A comparison of these results with those of other workers is presented.
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PMID:Secondary structure of Bombyx mori and Dictyostelium discoideum 5S rRNA from S1 nuclease and cobra venom ribonuclease susceptibility, and computer assisted analysis. 627 26

Using a modification of the Berk and Sharp S1 nuclease mapping procedure and by analyzing actin cDNA clones, we have examined the expression of several members of the 17-member multigene family encoding actin in Dictyostelium. The mapping procedure, which takes advantage of the fact that the actin genes are homologous in the protein-coding region but are very divergent in the proposed 5' untranslated region has enabled us to quantitate the relative expression of several genes during the Dictyostelium life cycle. We have shown that at least six of the 17 potential actin-coding sequences are expressed. One is not expressed at levels of more than 0.5--1% of total actin mRNA at the developmental times examined and appears to be a pseudogene. By quantitating the amount of actin mRNA in mRNA populations isolated from cells at various times in development, we have shown that four of the actin genes show different patterns of expression. Interestingly, three of the four genes appear to encode the same protein. We have also taken advantage of the S1 mapping procedure to identify the 5' ends of the actin mRNAs from four genes and have compared the sequences outside the 5' ends on these genes with the nucleotide sequences of seven other actin genes. We have identified homologous sequences in most of these genes that may be involved in initiation of transcription.
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PMID:Differential expression and 5' end mapping of actin genes in Dictyostelium. 689 15

Using S1 nuclease protection experiments and DNA sequencing, we have identified two intervening sequences (introns) within a Dictyostelium gene that codes for a low abundance class mRNA. The two introns are located within the protein coding region of this gene. Both are small (approximately 100 bp) and extremely (approximately 95%) A + T rich. The splice junction sequences are similar to the splice sites in other eukaryotes. Finally, we have shown that these introns are transcribed as part of a higher molecular weight nuclear precursor.
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PMID:Intervening sequences in a Dictyostelium gene that encodes a low abundance class mRNA. 746 23