1f27
From Proteopedia
(New page: 200px<br /> <applet load="1f27" size="450" color="white" frame="true" align="right" spinBox="true" caption="1f27, resolution 1.30Å" /> '''CRYSTAL STRUCTURE O...) |
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| - | [[Image:1f27.gif|left|200px]]<br /> | + | [[Image:1f27.gif|left|200px]]<br /><applet load="1f27" size="350" color="white" frame="true" align="right" spinBox="true" |
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caption="1f27, resolution 1.30Å" /> | caption="1f27, resolution 1.30Å" /> | ||
'''CRYSTAL STRUCTURE OF A BIOTIN-BINDING RNA PSEUDOKNOT'''<br /> | '''CRYSTAL STRUCTURE OF A BIOTIN-BINDING RNA PSEUDOKNOT'''<br /> | ||
==Overview== | ==Overview== | ||
| - | A pseudoknot-containing aptamer isolated from a pool of random sequence | + | A pseudoknot-containing aptamer isolated from a pool of random sequence molecules has been shown previously to represent an optimal RNA solution to the problem of binding biotin. The affinity of this RNA molecule is nonetheless orders of magnitude weaker than that of its highly evolved protein analogs, avidin and streptavidin. To understand the structural basis for biotin binding and to compare directly strategies for ligand recognition available to proteins and RNA molecules, we have determined the 1.3 A crystal structure of the aptamer complexed with its ligand. Biotin is bound at the interface between the pseudoknot's stacked helices in a pocket defined almost entirely by base-paired nucleotides. In comparison to the protein avidin, the aptamer packs more tightly around the biotin headgroup and makes fewer contacts with its fatty acid tail. Whereas biotin is deeply buried within the hydrophobic core in the avidin complex, the aptamer relies on a combination of hydrated magnesium ions and immobilized water molecules to surround its ligand. In addition to demonstrating fundamentally different approaches to molecular recognition by proteins and RNA, the structure provides general insight into the mechanisms by which RNA function is mediated by divalent metals. |
==About this Structure== | ==About this Structure== | ||
| - | 1F27 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with MG and BTN as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1F27 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=BTN:'>BTN</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F27 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: rna aptamer]] | [[Category: rna aptamer]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:33:57 2008'' |
Revision as of 10:33, 21 February 2008
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CRYSTAL STRUCTURE OF A BIOTIN-BINDING RNA PSEUDOKNOT
Overview
A pseudoknot-containing aptamer isolated from a pool of random sequence molecules has been shown previously to represent an optimal RNA solution to the problem of binding biotin. The affinity of this RNA molecule is nonetheless orders of magnitude weaker than that of its highly evolved protein analogs, avidin and streptavidin. To understand the structural basis for biotin binding and to compare directly strategies for ligand recognition available to proteins and RNA molecules, we have determined the 1.3 A crystal structure of the aptamer complexed with its ligand. Biotin is bound at the interface between the pseudoknot's stacked helices in a pocket defined almost entirely by base-paired nucleotides. In comparison to the protein avidin, the aptamer packs more tightly around the biotin headgroup and makes fewer contacts with its fatty acid tail. Whereas biotin is deeply buried within the hydrophobic core in the avidin complex, the aptamer relies on a combination of hydrated magnesium ions and immobilized water molecules to surround its ligand. In addition to demonstrating fundamentally different approaches to molecular recognition by proteins and RNA, the structure provides general insight into the mechanisms by which RNA function is mediated by divalent metals.
About this Structure
1F27 is a Protein complex structure of sequences from [1] with and as ligands. Full crystallographic information is available from OCA.
Reference
The 1.3 A crystal structure of a biotin-binding pseudoknot and the basis for RNA molecular recognition., Nix J, Sussman D, Wilson C, J Mol Biol. 2000 Mar 10;296(5):1235-44. PMID:10698630
Page seeded by OCA on Thu Feb 21 12:33:57 2008
Categories: Protein complex | Nix, J. | Sussman, D. | Wilson, C. | BTN | MG | Biotin-binding rna | Pseudoknot | Rna aptamer
