Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.26.4 (RNase H)
 2,751 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

RNase H is an endonuclease which cleaves RNA at points of hybridization with DNA. However, certain ambiguities exist in terms of its specificity and location of cleavage along the RNA strand. The analysis of RNase H reaction products of an oligoribonucleotide hairpin by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI/TOF-MS) is demonstrated. The oligoribonucleotide studied has a highly stable secondary structure which reduces the efficiency of hybridization with the chimeric oligonucleotide used to direct RNase H cleavage. By monitoring the reaction products under different conditions using MALDI/TOF-MS, the optimum variables for cleavage of this highly stable hairpin structure can be determined.
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PMID:Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for the analysis of RNase H cleavage products. 987 24

Current studies of lariat RNA structure and function are hindered by the lack of access to synthetic lariats. A novel approach to the synthesis of both DNA and RNA lariats is presented here. Noteworthy features of the methodology are the regiospecific formation of the 2'-5'-phosphodiester linkage, the unusual parallel stranded DNA/RNA hybrid (or parallel RNA/RNA duplex) that forms between an RNA template and a folded 22-nt DNA (or RNA) substrate, and the efficiency of the chemical ligation step at an adenosine branchpoint (50-80%). The DNA and RNA lariats were purified by polyacrylamide gel electrophoresis, and their structure and nucleotide composition were confirmed by MALDI-TOF mass spectrometry. Thermal denaturation as well as enzymatic and chemical hydrolysis fully supported the proposed lariat structures. Characterization of control parallel duplexes was conducted by gel shift assays and enzymatic degradation with RNase H. The successful synthesis of the lariat molecules described here will allow structural and biochemical studies aimed at better understanding the splicing and debranching mechanisms in which these unusual nucleic acids are involved.
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PMID:A novel approach to the synthesis of DNA and RNA lariats. 1797 85