title: Specificity of guanylic RNases to polynucleotide substrates.
abstract: Kinetic parameters kcat and KM were measured for cleavage of poly I, poly A, poly U, poly C and poly I poly C by guanyl-specific RNases Sa, Pb1 and T1 and compared with that of guanyl-preferential RNase Bi. Catalytic efficiencies of the investigated enzymes to polynucleotide substrates vary considerably. The structural basis for specificity of these RNases is discussed. A hypothesis is suggested that Ser-56 plays an important role in recognition of poly A by RNase Bi.
authors.affiliation: Institute of Molecular Biology of the Slovak Academy of Sciences, Bratislava, Czechoslovakia.
authors.forename: V
authors.initials: V
authors.lastname: Both
authors.forename: G P
authors.initials: GP
authors.lastname: Moiseyev
authors.forename: J
authors.initials: J
authors.lastname: Sevcik
mesh_terms: D001236:Aspergillus oryzae / Q000201:enzymology; D004722:Endoribonucleases / Q000378:metabolism*; D007700:Kinetics; D010407:Penicillium / Q000201:enzymology; D011119:Polynucleotides / Q000378:metabolism*; D016337:RNA, Catalytic / Q000378:metabolism*; D043262:Ribonuclease P; D006163:Ribonuclease T1 / Q000378:metabolism*; D012260:Ribonucleases / Q000378:metabolism*; D013304:Streptomyces aureofaciens / Q000201:enzymology; D013379:Substrate Specificity
chemical_list: D011119:Polynucleotides; D016337:RNA, Catalytic; D004722:Endoribonucleases; D012260:Ribonucleases; D043262:Ribonuclease P; D006163:Ribonuclease T1; C022542:ribonuclease S