GTP-dependent RNA 3'-terminal phosphate cyclase from the hyperthermophilic archaeon Pyrococcus furiosus

Genes Cells. 2011 Dec;16(12):1190-9. doi: 10.1111/j.1365-2443.2011.01561.x. Epub 2011 Nov 10.


We discovered that the PF1549 gene in Pyrococcus furiosus encodes a very heat-stable RNA 3'-terminal phosphate cyclase (Pf-Rtc). Although all previously reported Rtc proteins are ATP-dependent enzymes, we found that Pf-Rtc requires GTP for its cyclase activity at 95 °C. Low-level activation of the enzyme was also observed in the presence of dGTP but not other dNTPs, indicating that the guanine base is very important for Pf-Rtc activity. We analyzed a series of GTP analogues and found that the conversion from GTP to GMP is important for Pf-Rtc activity and that an excess of GMP inhibits this activity. Gel-shift analysis clearly showed that the RNA-binding activity of Pf-Rtc is totally dependent on the linear form of the 3'-terminal phosphate, with an apparent K(d) value of 20 nm at 95°C. Furthermore, we found that Pf-Rtc may contribute to GTP-dependent RNA ligation activity through the PF0027 protein (a 2'-5' RNA ligase-like protein in P. furiosus). The possible roles of Pf-Rtc and the importance of terminal phosphate structures in RNA are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cloning, Molecular
  • Electrophoretic Mobility Shift Assay
  • Escherichia coli
  • Guanosine Triphosphate / metabolism*
  • Hot Temperature
  • Kinetics
  • Ligases / chemistry
  • Ligases / genetics
  • Ligases / isolation & purification
  • Ligases / metabolism*
  • Molecular Sequence Data
  • Phosphates / metabolism*
  • Plasmids
  • Polynucleotide Ligases / genetics
  • Polynucleotide Ligases / metabolism*
  • Pyrococcus furiosus / enzymology*
  • Pyrococcus furiosus / genetics
  • RNA / genetics
  • RNA / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism*
  • Sequence Homology, Amino Acid
  • Transformation, Bacterial


  • Phosphates
  • Recombinant Proteins
  • RNA
  • Guanosine Triphosphate
  • Ligases
  • RNA 3'-terminal phosphate cyclase
  • Polynucleotide Ligases