1xmm
From Proteopedia
(New page: 200px<br /> <applet load="1xmm" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xmm, resolution 2.50Å" /> '''Structure of human ...) |
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caption="1xmm, resolution 2.50Å" /> | caption="1xmm, resolution 2.50Å" /> | ||
'''Structure of human Dcps bound to m7GDP'''<br /> | '''Structure of human Dcps bound to m7GDP'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Eukaryotic cells utilize DcpS, a scavenger decapping enzyme, to degrade | + | Eukaryotic cells utilize DcpS, a scavenger decapping enzyme, to degrade the residual cap structure following 3'-5' mRNA decay, thereby preventing the premature decapping of the capped long mRNA and misincorporation of methylated nucleotides in nucleic acids. We report the structures of DcpS in ligand-free form and in a complex with m7GDP. apo-DcpS is a symmetric dimer, strikingly different from the asymmetric dimer observed in the structures of DcpS with bound cap analogues. In contrast, and similar to the m7GpppG-DcpS complex, DcpS with bound m7GDP is an asymmetric dimer in which the closed state appears to be the substrate-bound complex, whereas the open state mimics the product-bound complex. Comparisons of these structures revealed conformational changes of both the N-terminal swapped-dimeric domain and the cap-binding pocket upon cap binding. Moreover, Tyr273 in the cap-binding pocket displays remarkable conformational changes upon cap binding. Mutagenesis and biochemical analysis suggest that Tyr273 seems to play an important role in cap binding and product release. Examination of the crystallographic B-factors indicates that the N-terminal domain in apo-DcpS is inherently flexible, and in a dynamic state ready for substrate binding and product release. |
==About this Structure== | ==About this Structure== | ||
| - | 1XMM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with PO4, M7G and G7M as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1XMM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=PO4:'>PO4</scene>, <scene name='pdbligand=M7G:'>M7G</scene> and <scene name='pdbligand=G7M:'>G7M</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XMM OCA]. |
==Reference== | ==Reference== | ||
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[[Category: scavenger decapping enzyme bound m7gdp]] | [[Category: scavenger decapping enzyme bound m7gdp]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:56:27 2008'' |
Revision as of 13:56, 21 February 2008
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Structure of human Dcps bound to m7GDP
Overview
Eukaryotic cells utilize DcpS, a scavenger decapping enzyme, to degrade the residual cap structure following 3'-5' mRNA decay, thereby preventing the premature decapping of the capped long mRNA and misincorporation of methylated nucleotides in nucleic acids. We report the structures of DcpS in ligand-free form and in a complex with m7GDP. apo-DcpS is a symmetric dimer, strikingly different from the asymmetric dimer observed in the structures of DcpS with bound cap analogues. In contrast, and similar to the m7GpppG-DcpS complex, DcpS with bound m7GDP is an asymmetric dimer in which the closed state appears to be the substrate-bound complex, whereas the open state mimics the product-bound complex. Comparisons of these structures revealed conformational changes of both the N-terminal swapped-dimeric domain and the cap-binding pocket upon cap binding. Moreover, Tyr273 in the cap-binding pocket displays remarkable conformational changes upon cap binding. Mutagenesis and biochemical analysis suggest that Tyr273 seems to play an important role in cap binding and product release. Examination of the crystallographic B-factors indicates that the N-terminal domain in apo-DcpS is inherently flexible, and in a dynamic state ready for substrate binding and product release.
About this Structure
1XMM is a Single protein structure of sequence from Homo sapiens with , and as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structures of human DcpS in ligand-free and m7GDP-bound forms suggest a dynamic mechanism for scavenger mRNA decapping., Chen N, Walsh MA, Liu Y, Parker R, Song H, J Mol Biol. 2005 Apr 8;347(4):707-18. PMID:15769464
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