Kinetics at a multifunctional RNA active site.

  title={Kinetics at a multifunctional RNA active site.},
  author={Fanglu Huang and Matthew A. Yarus},
  journal={Journal of molecular biology},
  volume={284 2},
Kinetics of a self-capping RNA, Iso6, have been investigated to constrain the catalytic mechanism. The role of phosphates has been examined by varying the number of phosphates on the nucleophilic attacking group or on the RNA. While the number of phosphates in the nucleophile affects capping kinetics, only KM but not kcat is altered. The KM values for GMP, GDP, GTP and ppppG are 200, 11, 13 and 31 microM, respectively. A reaction product, pyrophosphate, is also found to strongly inhibit RNA… CONTINUE READING