Discussion

In summary, we systematically screened a protein expression library from hyperthermophilic archaeon Pyrococcus furiosus ( P. furiosus) using a multi-structure oligo to search for novel RNA-binding proteins. And we found 21 RNA-binding protein candidates. In protein pool No.658, we found an RNA-binding activity. And we determined the gene PF1684 protein, which was annotated as acetylglutamate kinase is responsible for this RNA-binding activity. Interestingly, this RNA-binding activity is either coupled with nuclease activity or it may have an effect in alter the RNA oligo structure either directly or indirectly. It is also unknown what is the meaning of this kinase to be able to bind RNAs. In the future, we will determine the binding sites on both of the oligo RNA and the PF1684 protein for the ATP-independent RNA binding activity. We will also research on how the temperature may regulate this activity. Acknowledgement I thank Dr. Akio Kanai (IAB, Keio University) for supervising the work, Masaru Tomita for scientific encouragement and Sato Asako (IAB, Keio University) for technical assistance.