3mct
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(New page: 200px<br /><applet load="3mct" size="450" color="white" frame="true" align="right" spinBox="true" caption="3mct, resolution 2.0Å" /> '''VACCINIA METHYLTRANSF...)
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Revision as of 17:44, 20 November 2007
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VACCINIA METHYLTRANSFERASE VP39 COMPLEXED WITH M3CYT AND S-ADENOSYLHOMOCYSTEINE
Overview
We have determined, by high resolution x-ray analysis, 10 structures, comprising the mRNA cap-specific methyltransferase VP39 or specific, mutants thereof in the presence of methylated nucleobase analogs, (N1-methyladenine, N3-methyladenine, N1-methylcytosine, N3-methylcytosine), and their unmethylated counterparts, or nucleoside N7-methylguanosine., Together with solution affinity studies and previous crystallographic data, for N7-methylguanosine and its phosphorylated derivatives, these data, demonstrate that only methylated, positively charged bases are bound, indicating that their enhanced stacking with two aromatic side chains of, VP39 (Tyr 22 and Phe 180) plays a dominant role in cap recognition. Four, key features characterize this stacking interaction: (i) near perfect, parallel alignment between the sandwiched methylated bases and aromatic, side chains, (ii) substantial areas of overlap in the two-stacked rings, (iii) a 3.4-A interplanar spacing within the overlapping region, and (iv), positive charge in the heterocyclic nucleobase.
About this Structure
3MCT is a Single protein structure of sequence from Vaccinia virus with SAH and 3MC as ligands. Active as Polynucleotide adenylyltransferase, with EC number 2.7.7.19 Full crystallographic information is available from OCA.
Reference
mRNA cap recognition: dominant role of enhanced stacking interactions between methylated bases and protein aromatic side chains., Hu G, Gershon PD, Hodel AE, Quiocho FA, Proc Natl Acad Sci U S A. 1999 Jun 22;96(13):7149-54. PMID:10377383
Page seeded by OCA on Tue Nov 20 19:51:33 2007
Categories: Polynucleotide adenylyltransferase | Single protein | Vaccinia virus | Gershon, P.D. | Hodel, A.E. | Hu, G. | Quiocho, F.A. | 3MC | SAH | Complex (transferase/rna cap analog) | Methylated cytosine | Methyltransferase | Mrna processing | Poly(a) polymerase | Rna cap analog | Transcription | Vaccinia