1l9k
From Proteopedia
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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 with SO4 and SAH as ligands. Active as RNA-directed RNA polymerase, with EC number 2.7.7.48 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
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