title: Effect of low nucleotide concentrations on abortive elongation catalysed by wheat-germ RNA polymerase II.
abstract: A kinetic study of the effect of elongating nucleotide concentration on the reactions of abortive elongation catalysed by wheat-germ RNA polymerase II on a poly[d(A-T)] template suggests that the shift from abortive to productive elongation may involve the participation of at least two nucleotides, according to a mechanism very similar to that reported for Escherichia coli RNA polymerase. Experiments performed with non-complementary nucleotides with respect to the DNA template, and with substrate derivatives, allow an analysis of the substrate specificity during these reactions. Similar experiments performed with poly[d(A-A-T)].poly[d(T-T-A)] as template provide a starting point for a better understanding of the effect of DNA sequence on the rates of abortive and productive elongation catalysed by the plant enzyme.
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D003839:Deoxyadenosines / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D009711:Nucleotides / Q000378:metabolism* / Q000494:pharmacology; D009843:Oligoribonucleotides / Q000096:biosynthesis*; D011063:Poly A-U / Q000378:metabolism; D011067:Poly dA-dT / Q000494:pharmacology; D012319:RNA Polymerase II / Q000378:metabolism*; D014908:Triticum / Q000201:enzymology*
chemical_list: D003839:Deoxyadenosines; D009711:Nucleotides; D009843:Oligoribonucleotides; D011063:Poly A-U; D011067:Poly dA-dT; C053104:uridylyl-(3'-5')-adenylyl-(3'-5')uridine; D000255:Adenosine Triphosphate; D012319:RNA Polymerase II