1ckn: Difference between revisions
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Revision as of 15:54, 30 October 2007
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STRUCTURE OF GUANYLYLATED MRNA CAPPING ENZYME COMPLEXED WITH GTP
OverviewOverview
We have solved the crystal structure of an mRNA capping enzyme at 2.5 A, resolution. The enzyme comprises two domains with a deep, but narrow, cleft between them. The two molecules in the crystallographic asymmetric, unit adopt very different conformations; both contain a bound GTP, but one, protein molecule is in an open conformation while the other is in a closed, conformation. Only in the closed conformation is the enzyme able to bind, manganese ions and undergo catalysis within the crystals to yield the, covalent guanylated enzyme intermediate. These structures provide direct, evidence for a mechanism that involves a significant conformational change, in the enzyme during catalysis.
About this StructureAbout this Structure
1CKN is a [Single protein] structure of sequence from [Paramecium bursaria chlorella virus 1] with MN, SO4 and GTP as [ligands]. Active as [mRNA guanylyltransferase], with EC number [2.7.7.50]. Structure known Active Sites: GMA and GMB. Full crystallographic information is available from [OCA].
ReferenceReference
X-ray crystallography reveals a large conformational change during guanyl transfer by mRNA capping enzymes., Hakansson K, Doherty AJ, Shuman S, Wigley DB, Cell. 1997 May 16;89(4):545-53. PMID:9160746
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