The effect of divalent Mg2+ and Mn2+ cations on the elongation of ApU, UpA and their 3'O- and 5'O-phosphonylmethyl analogues by RNA polymerase holoenzyme to the corresponding trinucleo-tides on a poly(dA-dT) template was investigated. In contrast to Mgz+ ions, Mn2+ ions enhance abortive trinucleotide synthesis. This effect is more pronounced with phosphonylmethyl analogues. The core enzyme cannot catalyze the elongation of either (2'5' UpA or phosphonylmethyl analogues. The localization of the divalent cation activator, as well as the role of the σ subunit at the catalytic centre of the holoenzyme, is discussed.
- Core polymerase
- Divalent cations
- Phosphonate dinucleotide primers
ASJC Scopus subject areas