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)

The structure of the chromosomal gene encoding rat aldolase isozyme B has been elucidated by sequence analysis of cloned genomic DNA. This gene comprises about 14 X 10(3) base-pairs of DNA, and is separated into nine exons by eight intervening sequences. A presumed transcription-initiation site was assigned by S1 nuclease protection mapping, and T-A-T-A and C-C-A-A-T boxes were found to be 25 and 126 base-pairs, respectively, upstream from this initiation site. There are three characteristic sequences of 100 to 200 base-pairs within the region of 870 base-pairs flanking the 5' side of the gene. These sequences are flanked on either side by direct repeats and terminate with an A-rich stretch of nucleotides. One of them has block homology with a region in an "ID sequence", which is reported to be an element for tissue-specific gene regulation and differentiation. The other two are analogous at the sequence organizational level with a sort of dispersed repeat, the "Alu family". These features suggest that these regions are involved in gene regulation and, also, imply evolutionary events such as duplication or insertion. Comparison of this gene sequence with the rabbit aldolase A complementary DNA sequence revealed some bias in the frequency of nucleotide replacement among the exons, suggesting selective evolutionary conservation of particular exons encoding functional domains. Comparison with the human aldolase B complementary DNA sequence revealed no such tendency; the homology between the two sequences was very high (about 89%), and nucleotide replacements were randomly distributed throughout the protein-coding region.
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PMID:Structure and genomic organization of the rat aldolase B gene. 258 98

Southern blot analysis of human genomic DNA hybridized with a coding region aldolase A cDNA probe (600 bases) revealed four restriction fragments with EcoRI restriction enzyme: 7.8 kb, 13 kb, 17 kb and greater than 30 kb. By human-hamster hybrid analysis (Southern technique) the principal fragments, 7.8 kb, 13 kb, greater than 30 kb, were localized to chromosomes 10, 16 and 3 respectively. The 17-kb fragment was very weak in intensity; it co-segregated with the greater than 30-kb fragment and is probably localized on chromosome 3 with the greater than 30-kb fragment. Analysis of a second aldolase A labelled probe protected against S1 nuclease digestion by RNAs from different hybrid cells, indicated the presence of aldolase A mRNAs in hybrid cells containing only chromosome 16. Under the stringency conditions used, the EcoRI sequences detected by the coding region aldolase A cDNA probe did not correspond to aldolase B or C. The 7.8-kb and greater than 30-kb EcoRI sequences, localized respectively on chromosomes 10 and 3, correspond to aldolase A pseudogenes; the 13-kb EcoRI sequence localized on chromosome 16 corresponds to the aldolase active gene. The fact that the aldolase A gene and pseudogenes are located on three different chromosomes supports the hypothesis that the pseudogenes originated from aldolase A mRNAs, copied into DNA and integrated in unrelated chromosomal loci.
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PMID:Localization of the active gene of aldolase on chromosome 16, and two aldolase A pseudogenes on chromosomes 3 and 10. 282 24

The complete nucleotide sequence of the rat aldolase A isozyme gene, including the 5' and 3' flanking sequences, was determined. The gene comprises ten exons, spans 4827 base-pairs and occurs in a single copy per haploid rat genome. The genomic DNA sequence was compared with those of three species of rat aldolase A mRNA (mRNAs I, II and III) that have been found to differ from each other only in the 5' non-coding region and to be expressed tissue-specifically. It revealed that the first exon (exon M1) encodes the 5' non-coding sequence of mRNA I, while the second exon (exon AH1) encodes those of mRNAs II and III and the following eight exons (exons 2 to 9) are shared commonly by all the mRNA species. These results allowed us to conclude that mRNA I and mRNAs II, III were generated from a single aldolase A gene by alternative usage of exon M1 or exon AH1 in addition to exons 2 to 9. S1 nuclease mapping of the 5' ends of their precursor RNAs suggested that these three mRNA species were transcribed from three different initiation sites on the single gene.
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PMID:Expression of three mRNA species from a single rat aldolase A gene, differing in their 5' non-coding regions. 378 5