Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.1 (RNase)
 16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

RNases III are a family of double-stranded RNA (dsRNA) endoribonucleases involved in the processing and decay of a large number of cellular RNAs as well as in RNA interference. The dsRNA substrates of Saccharomyces cerevisiae RNase III (Rnt1p) are capped by tetraloops with the consensus sequence AGNN, which act as the primary docking site for the RNase. We have solved the solution structures of two RNA hairpins capped by AGNN tetraloops, AGAA and AGUU, using NMR spectroscopy. Both tetraloops have the same overall structure, in which the backbone turn occurs on the 3' side of the syn G residue in the loop, with the first A and G in a 5' stack and the last two residues in a 3' stack. A non-bridging phosphate oxygen and the universal G which are essential for Rnt1p binding are strongly exposed. The compared biochemical and structural analysis of various tetraloop sequences defines a novel family of RNA tetraloop fold with the consensus (U/A)GNN and implicates this conserved structure as the primary determinant for specific recognition of Rnt1p substrates.
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PMID:A novel family of RNA tetraloop structure forms the recognition site for Saccharomyces cerevisiae RNase III. 1174

Gel-based oligonucleotide microarray approach was developed for quantitative profiling of binding affinity of a protein to single-stranded DNA (ssDNA). To demonstrate additional capabilities of this method, we analyzed the binding specificity of ribonuclease (RNase) binase from Bacillus intermedius (EC 3.1.27.3) to ssDNA using generic hexamer oligodeoxyribonucleotide microchip. Single-stranded octamer oligonucleotides were immobilized within 3D hemispherical gel pads. The octanucleotides in individual pads 5'-{N}N(1)N(2)N(3)N(4)N(5)N(6){N}-3' consisted of a fixed hexamer motif N(1)N(2)N(3)N(4)N(5)N(6) in the middle and variable parts {N} at the ends, where {N} represent A, C, G and T in equal proportions. The chip has 4096 pads with a complete set of hexamer sequences. The affinity was determined by measuring dissociation of the RNase-ssDNA complexes with the temperature increasing from 0 degrees C to 50 degrees C in quasi-equilibrium conditions. RNase binase showed the highest sequence-specificity of binding to motifs 5'-NNG(A/T/C)GNN-3' with the order of preference: GAG > GTG > GCG. High specificity towards G(A/T/C)G triplets was also confirmed by measuring fluorescent anisotropy of complexes of binase with selected oligodeoxyribonucleotides in solution. The affinity of RNase binase to other 3-nt sequences was also ranked. These results demonstrate the applicability of the method and provide the ground for further investigations of nonenzymatic functions of RNases.
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PMID:Gel-based oligonucleotide microarray approach to analyze protein-ssDNA binding specificity. 1847 29