1tej
From Proteopedia
(New page: 200px<br /><applet load="1tej" size="450" color="white" frame="true" align="right" spinBox="true" caption="1tej, resolution 1.90Å" /> '''Crystal structure of...) |
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| - | [[Image:1tej.gif|left|200px]]<br /><applet load="1tej" size=" | + | [[Image:1tej.gif|left|200px]]<br /><applet load="1tej" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1tej, resolution 1.90Å" /> | caption="1tej, resolution 1.90Å" /> | ||
'''Crystal structure of a disintegrin heterodimer at 1.9 A resolution.'''<br /> | '''Crystal structure of a disintegrin heterodimer at 1.9 A resolution.'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Disintegrins constitute a family of potent polypeptide inhibitors of | + | Disintegrins constitute a family of potent polypeptide inhibitors of integrins. Integrins are transmembrane heterodimeric molecules involved in cell-cell and cell-extracellular matrix interactions. They are involved in many diseases such as cancer and thrombosis. Thus, disintegrins have a great potential as anticancer and antithrombotic agents. A novel heterodimeric disintegrin was isolated from the venom of saw-scaled viper (Echis carinatus) and was crystallized. The crystals diffracted to 1.9 A resolution and belonged to space group P4(3)2(1)2. The data indicated the presence of a pseudosymmetry. The structure was solved by applying origin shifts to the disintegrin homodimer schistatin solved in space group I4(1)22 with similar cell dimensions. The structure refined to the final R(cryst)/R(free) factors of 0.213/0.253. The notable differences are observed between the loops, (Gln39-Asp48) containing the important Arg42-Gly43-Asp44, of the present heterodimer and schistatin. These differences are presumably due to the presence of two glycines at positions 43 and 46 that allow the molecule to adopt variable conformations. A comparative analysis of the surface-charge distributions of various disintegrins showed that the charge distribution on monomeric disintegrins occurred uniformly over the whole surface of the molecule, while in the dimeric disintegrins, the charge is distributed only on one face. Such a feature may be important in the binding of two integrins to a single dimeric disintegrin. The phylogenetic analysis developed on the basis of amino acid sequence and three-dimensional structures indicates that the protein diversification and evolution presumably took place from the medium disintegrins and both the dimeric and short disintegrins evolved from them. |
==About this Structure== | ==About this Structure== | ||
| - | 1TEJ is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Echis_carinatus Echis carinatus]. Full crystallographic information is available from [http:// | + | 1TEJ is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Echis_carinatus Echis carinatus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TEJ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Kaur, P.]] | [[Category: Kaur, P.]] | ||
[[Category: Perbandt, M.]] | [[Category: Perbandt, M.]] | ||
| - | [[Category: Singh, T | + | [[Category: Singh, T P.]] |
[[Category: Yadav, S.]] | [[Category: Yadav, S.]] | ||
[[Category: cryatal structure]] | [[Category: cryatal structure]] | ||
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[[Category: heterodimer]] | [[Category: heterodimer]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:12:42 2008'' |
Revision as of 13:12, 21 February 2008
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Crystal structure of a disintegrin heterodimer at 1.9 A resolution.
Overview
Disintegrins constitute a family of potent polypeptide inhibitors of integrins. Integrins are transmembrane heterodimeric molecules involved in cell-cell and cell-extracellular matrix interactions. They are involved in many diseases such as cancer and thrombosis. Thus, disintegrins have a great potential as anticancer and antithrombotic agents. A novel heterodimeric disintegrin was isolated from the venom of saw-scaled viper (Echis carinatus) and was crystallized. The crystals diffracted to 1.9 A resolution and belonged to space group P4(3)2(1)2. The data indicated the presence of a pseudosymmetry. The structure was solved by applying origin shifts to the disintegrin homodimer schistatin solved in space group I4(1)22 with similar cell dimensions. The structure refined to the final R(cryst)/R(free) factors of 0.213/0.253. The notable differences are observed between the loops, (Gln39-Asp48) containing the important Arg42-Gly43-Asp44, of the present heterodimer and schistatin. These differences are presumably due to the presence of two glycines at positions 43 and 46 that allow the molecule to adopt variable conformations. A comparative analysis of the surface-charge distributions of various disintegrins showed that the charge distribution on monomeric disintegrins occurred uniformly over the whole surface of the molecule, while in the dimeric disintegrins, the charge is distributed only on one face. Such a feature may be important in the binding of two integrins to a single dimeric disintegrin. The phylogenetic analysis developed on the basis of amino acid sequence and three-dimensional structures indicates that the protein diversification and evolution presumably took place from the medium disintegrins and both the dimeric and short disintegrins evolved from them.
About this Structure
1TEJ is a Protein complex structure of sequences from Echis carinatus. Full crystallographic information is available from OCA.
Reference
Crystal structure of the disintegrin heterodimer from saw-scaled viper (Echis carinatus) at 1.9 A resolution., Bilgrami S, Yadav S, Kaur P, Sharma S, Perbandt M, Betzel C, Singh TP, Biochemistry. 2005 Aug 23;44(33):11058-66. PMID:16101289
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