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 nuclear non-polyadenylated RNA from HeLa cells infected with adenovirus-2 was examined for the presence of molecules containing the first intervening sequence (IVS1) of the major late premessenger RNA. Four molecules with the approximate size of free IVS1 in sucrose gradients (1021 nucleotides) were separated by polyacrylamide gel electrophoresis and characterized by complementary methods: S1 nuclease mapping, susceptibility to debranching enzyme, RNAase-H-directed cleavage. The results indicate that the most abundant RNA form is the excised lariat IVS1. We also find linear IVS1 and a randomly nicked lariat, the latter probably being made during RNA isolation. The fourth RNA is a leader 1-IVS1 molecule. No truncated IVS1 which might indicate that IVS1 is excised by several cycle of cleavage-ligation was detected. A study of the distribution of the four RNAs in hnRNP shows that they are part of RNPs of about 70 S. However, each RNP has distinct sedimentation characteristics and sensitivity to salt dissociation. Together, the results suggest that the excised lariat IVS1 is released from the large late premRNP under the form of a 70 S RNP, where it is linearized.
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PMID:Nuclear non-polyadenylated RNAs containing the first intervening sequence of the major late premessenger RNA from adenovirus-2: characterization and distribution in ribonucleoproteins. 303 61

We present evidence that addition of the 35 nucleotide spliced leader (SL) to the 5' end of T. brucei mRNAs occurs via trans RNA splicing. A 100 nucleotide fragment of the 135 base SL RNA (100-mer) is revealed by S1 nuclease analysis of total and poly(A)+ RNA. This 100-mer is not detected by Northern hybridization analysis, indicating that it does not exist free in the cell. The 5' end of the 100-mer maps precisely to the conserved splice junction sequence of the SL RNA. Purified debranching enzyme releases this 100-mer RNA as a free, 100 nucleotide species. This indicates that the 100-mer is covalently linked to poly(A)+ RNA by a 2'-5' phosphodiester bond, that the branched intermediate has a discontinuous intron or Y structure (rather than a lariat), which is expected of a trans-spliced mRNA, and that the SL RNA is indeed the donor of the SL sequence to trypanosome mRNAs.
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PMID:Identification of a novel Y branch structure as an intermediate in trypanosome mRNA processing: evidence for trans splicing. 377 35