This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1l9k
From Proteopedia
| |||||||
| , resolution 2.40Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Gene: | NS5 New Guinea C (Dengue virus type 3) | ||||||
| Activity: | RNA-directed RNA polymerase, with EC number 2.7.7.48 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
dengue methyltransferase
Overview
Viruses represent an attractive system with which to study the molecular basis of mRNA capping and its relation to the RNA transcription machinery. The RNA-dependent RNA polymerase NS5 of flaviviruses presents a characteristic motif of S-adenosyl-L-methionine-dependent methyltransferases at its N-terminus, and polymerase motifs at its C-terminus. The crystal structure of an N-terminal fragment of Dengue virus type 2 NS5 is reported at 2.4 A resolution. We show that this NS5 domain includes a typical methyltransferase core and exhibits a (nucleoside-2'-O-)-methyltransferase activity on capped RNA. The structure of a ternary complex comprising S-adenosyl-L-homocysteine and a guanosine triphosphate (GTP) analogue shows that 54 amino acids N-terminal to the core provide a novel GTP-binding site that selects guanine using a previously unreported mechanism. Binding studies using GTP- and RNA cap-analogues, as well as the spatial arrangement of the methyltransferase active site relative to the GTP-binding site, suggest that the latter is a specific cap-binding site. As RNA capping is an essential viral function, these results provide a structural basis for the rational design of drugs against the emerging flaviviruses.
About this Structure
1L9K is a Single protein structure of sequence from Dengue virus type 3. Full crystallographic information is available from OCA.
Reference
An RNA cap (nucleoside-2'-O-)-methyltransferase in the flavivirus RNA polymerase NS5: crystal structure and functional characterization., Egloff MP, Benarroch D, Selisko B, Romette JL, Canard B, EMBO J. 2002 Jun 3;21(11):2757-68. PMID:12032088
Page seeded by OCA on Thu Mar 20 12:28:12 2008
