Question

1. Why the ribozyme interacts with one of the two non bridging phosphate oxygen atoms at the cleavage site, but not via inner sphere coordination with a divalent metal ion at the active site?

2. Why pistol ribozymes do not require inner sphere coordination of divalent metal ions anywhere in the structure, including at the active site?

3. Why the pistol ribozyme contract with one of the two non bridging oxygen atoms in a way that is strongly disrupted by the presence of sulfur?

Thank you

Answer 1

1)Here Substitution nucleophilic attack takes place attacking the bridges phosphate group

causing oxygen atom to leave the group.

2) Metal ions in pistol ribozyme contribute just to maintain the configuration of the structure or

just to electrostatic stabilization and the activity of ribozyme takes place in the absence of

metal ions.Studies proved that with very less concentration of metal ions the biochemical

reactions do occur.

3)Similar to many catalytic reactions taking place,involve internal phosphoester transfer

between molecules, the same action is involved in the activity of pistol ribozyme.