Previous Article | Next Article 
Journal of Virology, February 2001, p. 1744-1750, Vol. 75, No. 4
0022-538X/01/$04.00+0 DOI: 10.1128/JVI.75.4.1744-1750.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
RNA Triphosphatase Component of the mRNA Capping Apparatus
of Paramecium bursaria Chlorella Virus 1
C. Kiong
Ho,
Chunling
Gong, and
Stewart
Shuman*
Molecular Biology Program, Sloan-Kettering
Institute, New York, New York 10021
Received 24 October 2000/Accepted 16 November 2000
Paramecium bursaria chlorella virus 1 (PBCV-1) elicits
a lytic infection of its unicellular green alga host. The 330-kbp viral genome has been sequenced, yet little is known about how viral mRNAs
are synthesized and processed. PBCV-1 encodes its own mRNA guanylyltransferase, which catalyzes the addition of GMP to the 5'
diphosphate end of RNA to form a GpppN cap structure. Here we report
that PBCV-1 encodes a separate RNA triphosphatase (RTP) that catalyzes
the initial step in cap synthesis: hydrolysis of the
-phosphate
of triphosphate-terminated RNA to generate an RNA diphosphate
end. We exploit a yeast-based genetic system to show that
Chlorella virus RTP can function as a cap-forming enzyme in
vivo. The 193-amino-acid Chlorella virus RTP is the
smallest member of a family of metal-dependent phosphohydrolases that
includes the RNA triphosphatases of fungi and other large
eukaryotic DNA viruses (poxviruses, African swine fever virus, and
baculoviruses). Chlorella virus RTP is more similar in
structure to the yeast RNA triphosphatases than to the enzymes of
metazoan DNA viruses. Indeed, PBCV-1 is unique among DNA viruses in
that the triphosphatase and guanylyltransferase steps of cap formation
are catalyzed by separate viral enzymes instead of a single viral
polypeptide with multiple catalytic domains.
*
Corresponding author. Mailing address: Molecular
Biology Proram, Sloan-Kettering Institute, 1275 York Ave., New
York, NY 10021. Phone: (212) 639-7145. Fax: (212) 717-3623. E-mail: s-shuman{at}ski.mskc.org.
Journal of Virology, February 2001, p. 1744-1750, Vol. 75, No. 4
0022-538X/01/$04.00+0 DOI: 10.1128/JVI.75.4.1744-1750.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Souliere, M. F., Perreault, J.-P., Bisaillon, M.
(2008). Magnesium-binding studies reveal fundamental differences between closely related RNA triphosphatases. Nucleic Acids Res
36: 451-461
[Abstract]
[Full Text]
-
Gong, C., Martins, A., Shuman, S.
(2003). Structure-Function Analysis of Trypanosoma brucei RNA Triphosphatase and Evidence for a Two-metal Mechanism. J. Biol. Chem.
278: 50843-50852
[Abstract]
[Full Text]
-
Bisaillon, M., Bougie, I.
(2003). Investigating the Role of Metal Ions in the Catalytic Mechanism of the Yeast RNA Triphosphatase. J. Biol. Chem.
278: 33963-33971
[Abstract]
[Full Text]
-
Takagi, T., Cho, E.-J., Janoo, R. T. K., Polodny, V., Takase, Y., Keogh, M.-C., Woo, S.-A., Fresco-Cohen, L. D., Hoffman, C. S., Buratowski, S.
(2002). Divergent Subunit Interactions among Fungal mRNA 5'-Capping Machineries. Eukaryot Cell
1: 448-457
[Abstract]
[Full Text]
-
Gong, C., Shuman, S.
(2002). Chlorella Virus RNA Triphosphatase. MUTATIONAL ANALYSIS AND MECHANISM OF INHIBITION BY TRIPOLYPHOSPHATE. J. Biol. Chem.
277: 15317-15324
[Abstract]
[Full Text]
-
Martins, A., Shuman, S.
(2001). Mutational Analysis of Baculovirus Capping Enzyme Lef4 Delineates an Autonomous Triphosphatase Domain and Structural Determinants of Divalent Cation Specificity. J. Biol. Chem.
276: 45522-45529
[Abstract]
[Full Text]
-
Ho, C. K., Shuman, S.
(2001). Trypanosoma brucei RNA Triphosphatase. ANTIPROTOZOAL DRUG TARGET AND GUIDE TO EUKARYOTIC PHYLOGENY. J. Biol. Chem.
276: 46182-46186
[Abstract]
[Full Text]
-
Ho, C. K., Shuman, S.
(2001). A yeast-like mRNA capping apparatus in Plasmodiumfalciparum. Proc. Natl. Acad. Sci. USA
10.1073/pnas.061636198v1
[Abstract]
[Full Text]
-
SHUMAN, S.
(2001). The mRNA Capping Apparatus as Drug Target and Guide to Eukaryotic Phylogeny. Cold Spring Harb Symp Quant Biol
66: 301-312
[Abstract]
-
Bisaillon, M., Shuman, S.
(2001). Structure-Function Analysis of the Active Site Tunnel of Yeast RNA Triphosphatase. J. Biol. Chem.
276: 17261-17266
[Abstract]
[Full Text]
-
Bisaillon, M., Shuman, S.
(2001). Functional Groups Required for the Stability of Yeast RNA Triphosphatase in Vitro and in Vivo. J. Biol. Chem.
276: 30514-30520
[Abstract]
[Full Text]
-
Hausmann, S., Vivares, C. P., Shuman, S.
(2002). Characterization of the mRNA Capping Apparatus of the Microsporidian Parasite Encephalitozoon cuniculi. J. Biol. Chem.
277: 96-103
[Abstract]
[Full Text]
-
Ho, C. K., Shuman, S.
(2001). A yeast-like mRNA capping apparatus in Plasmodiumfalciparum. Proc. Natl. Acad. Sci. USA
98: 3050-3055
[Abstract]
[Full Text]