title: Rapid RNA sequencing: nucleases from Staphylococcus aureus and Neurospora crassa discriminate between uridine and cytidine.
abstract: Using end-labelled RNA, significant changes in base specificity of three nucleases have been detected under defined conditions. Staphylococcus aureus nuclease at pH 3.5 without Ca++ cleaves all Pyr-N bonds more uniformly and efficiently than RNase A, without any preference for Pyr-A bonds. At pH 7.5 in 10 mM Ca++ this enzyme cleaves all N-C and N-G bonds slowly, whereas N-U and N-A bonds are hydrolyzed rapidly. Hence, the base at the 3'- or at the 5'-side of a phosphodiester bond can determine the base specificity of S. aureus nuclease. - In absence of urea, Neurospora crassa endonuclease cleaves all phosphodiester bonds, but leaves all C-N bonds intact in 7 M urea. - RNase U2 at pH 3.5 cleaves A-N bonds more efficiently than at pH 5.0.
mesh_terms: D001483:Base Sequence; D002118:Calcium / Q000494:pharmacology; D003562:Cytidine / Q000032:analysis*; D009491:Neurospora / Q000201:enzymology*; D009492:Neurospora crassa / Q000201:enzymology*; D012313:RNA; D012260:Ribonucleases / Q000378:metabolism*; D012265:Ribonucleotides / Q000032:analysis; D013211:Staphylococcus aureus / Q000201:enzymology*; D014529:Uridine / Q000032:analysis*
chemical_list: D012265:Ribonucleotides; D003562:Cytidine; D012313:RNA; D012260:Ribonucleases; D002118:Calcium; D014529:Uridine