S1411S, 3'-0 -Me-7mG(ppp)G RNA Cap Structure Analog (ARCA) - 25 A260 units

Blocking of the 3´ -hydroxyl of m⁷G with 3´-0-Me assures that the capped transcripts are homogeneous. The 3´ - hydroxyl of the non-methylated G is the only 3´ - hydroxyl available for initiation.

The 5´terminal m7G cap present on most eukaryotic mRNAs promotes translation in vitro at the initiation level. For most RNAs, elimination of the cap structure causes a loss of stability, especially against exonuclease degradation, and a decrease in the formation of the initiation complex of mRNAs for protein synthesis. Certain prokaryotic mRNAs containing a 5´ terminal cap structure are translated as efficiently as or more efficiently than eukaryotic mRNAs in a eukaryotic cell-free protein synthesizing system. Also a cap requirement has been observed for splicing eukaryotic substrate RNAs.

A method using E. coli RNA Polymerase primed with m⁷G(5´)ppp(5´)G or m⁷G(5´)ppp(5´)A for an efficient in vitro synthesis of capped RNAs has been developed by Contreas. Larger amounts of capped RNAs are produced by transcription systems using SP6 RNA Polymerase primed with m⁷G(5´)ppp(5´)G.

Sequence

3'-O-Me-7mG(5')ppp(5')G