title: Synthesis of mono- and dinucleotide photoaffinity probes of ribonucleic acid polymerase.
abstract: The abortive initiation reaction of RNA polymerase has been used to prepare adenylyl-(3'--5')-uridine 5'-phosphate (pApU) in 74% yield from AMP and UTP. The reactive intermediate p-azidophenyl phosphorimidazolidate has been prepared by starting from p-nitrophenyl phosphate. Reaction of this compound with the terminal phosphates of adenosine 5'-phosphate and adenylyl-(3'--5')-uridine 5'-phosphate gives the corresponding beta-substituted 5'-diphosphates. These products are incorporated into the 5' (leading) end of RNA by RNA polymerase (Escherichia coli) and can be photoactivated at a specific stage of RNA elongation. The dinucleotide photoaffinity label beta-(4-azidophenyl) adenylyl-(3'--5')-uridine 5'-diphosphate stimulates RNA synthesis more strongly than adenylyl-(3'--5')-uridine.
mesh_terms: D000244:Adenosine Diphosphate / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology; D000345:Affinity Labels / Q000138:chemical synthesis* / Q000494:pharmacology; D001386:Azides / Q000138:chemical synthesis* / Q000494:pharmacology; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D009841:Oligonucleotides / Q000138:chemical synthesis*; D009843:Oligoribonucleotides / Q000138:chemical synthesis* / Q000494:pharmacology; D010777:Photochemistry; D011067:Poly dA-dT; D012313:RNA / Q000096:biosynthesis*
chemical_list: D000345:Affinity Labels; D001386:Azides; D009841:Oligonucleotides; D009843:Oligoribonucleotides; C030183:adenylyl-(3'-5')-uridine 5'-phosphate; D011067:Poly dA-dT; D000244:Adenosine Diphosphate; D012313:RNA; C030185:beta-(4-azidophenyl)adenylyl-(3'-5')-uridine 5'-diphosphate; C030186:beta-(4-azidophenyl)adenosine 5'-diphosphate; C030184:4-azidophenylphosphorimidazolidate; D012321:DNA-Directed RNA Polymerases