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

The structural gene encoding human 3 beta-hydroxysteroid dehydrogenase/delta 5----4-isomerase (3 beta HSD) was isolated from a human EMBL3 genomic library. The gene encompasses approximately 8 kilobases of DNA and is comprised of two large introns and three exons encoding amino acid residues 1-48, 49-103, and 104-373, respectively. The exonic sequence is identical to that of the cDNA that we previously isolated and expressed in COS 1 cells. DNA sequence analysis reveals a putative TATA (TATATAA) motif 26 basepairs up-stream of the beginning of exon I, as determined by S1 nuclease protection analysis. However, primer extension analysis using poly(A)+ RNA isolated from both placenta and corpora lutea indicates that the RNA initiates up-stream of the putative TATA motif, and that an additional 53-basepair exon, which is untranslated, is present 5' to the first coding exon. Southern hybridization analysis of genomic DNA using a single exon probe suggests that there may be more than one copy of the gene in the human genome. In addition, we confirm from Southern analysis of genomic DNA isolated from human x hamster somatic cell hybrids that the gene is located on human chromosome 1. These findings will provide a foundation for the characterization of apparent 3 beta HSD clinical deficiencies when these are due to a mutation in the structural gene.
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PMID:Structural analysis of the gene encoding human 3 beta-hydroxysteroid dehydrogenase/delta 5----4-isomerase. 208 86

The enzyme 3 beta-hydroxysteroid dehydrogenase (3 betaHSD) is essential for all steroid hormone biosynthesis. Six distinct 3 betaHSD cDNAs in the mouse (3 betaHSD I-VI) have been isolated previously. This study reports the isolation of genes or partial genes encoding the 3 betaHSDI, II, III, and IV isoforms. Characterization of the genes revealed that they consist of four exons, the same structure that has been observed for characterized human 3 betaHSD genes. Primer extension and nuclease S1 analysis identified the start sites of transcription of Hsd3b -1 and -4. The proximal promoter regions of Hsd3b-1 and -4 were sequenced and putative cis-acting sequences were determined. Previously, we reported that the then known 3 betaHSD genes (3 betaHSD I-IV) were located in a small region of mouse chromosome 3. To analyze this locus further, six yeast artificial chromosome clones containing the 3 betaHSD sequence were identified. One clone appears to contain the complete 3 betaHSD locus within its 1,400-kbp insert. Further analysis of this YAC, along with analysis of mouse genomic DNA by pulsed-field gel electrophoresis, suggests all members of the 3 betaHSD gene family may be contained on a 400-kbp fragment.
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PMID:Isolation and characterization of several members of the murine Hsd3b gene family. 892 13