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GTP‐dependent RNA 3′‐terminal phosphate cyclase from the hyperthermophilic archaeon Pyrococcus furiosus
Author(s) -
Sato Asako,
Soga Tomoyoshi,
Igarashi Kaori,
Takesue Kanako,
Tomita Masaru,
Kanai Akio
Publication year - 2011
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/j.1365-2443.2011.01561.x
Subject(s) - pyrococcus furiosus , gtp' , biochemistry , rna , biology , gtpase , rna ligase , guanine , nucleotide , enzyme , microbiology and biotechnology , archaea , gene
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 n m 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.