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 β-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 β-(4-azidophenyl) adenylyl-(3′-5′)-uridine 5′-diphosphate stimulates RNA synthesis more strongly than adenylyl-(3′-5′)-uridine.
|Original language||English (US)|
|Number of pages||7|
|State||Published - 1981|
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