1cf5
From Proteopedia
(New page: 200px<br /><applet load="1cf5" size="450" color="white" frame="true" align="right" spinBox="true" caption="1cf5, resolution 2.550Å" /> '''BETA-MOMORCHARIN ST...) |
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| - | [[Image:1cf5.gif|left|200px]]<br /><applet load="1cf5" size=" | + | [[Image:1cf5.gif|left|200px]]<br /><applet load="1cf5" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1cf5, resolution 2.550Å" /> | caption="1cf5, resolution 2.550Å" /> | ||
'''BETA-MOMORCHARIN STRUCTURE AT 2.55 A'''<br /> | '''BETA-MOMORCHARIN STRUCTURE AT 2.55 A'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Beta-Momorcharin (Mr approximately 29 kDa) is a single-chained | + | Beta-Momorcharin (Mr approximately 29 kDa) is a single-chained ribosome-inactivating protein (RIP) with a branched hexasaccharide bound to Asn51. The crystal structure of beta-momorcharin has been determined using the molecular-replacement method and refined to 2. 55 A resolution. The final structural model gave an R factor of 17. 2% and root-mean-square deviations of 0.016 A and 1.76 degrees from ideal bond lengths and bond angles, respectively. beta-Momorcharin contains nine alpha-helices, two 310 helices and three beta-sheets, and its overall structure is similar to those of other single-chained RIPs. Residues Tyr70, Tyr109, Glu158 and Arg161 are expected to define the active site of beta-momorcharin as an rRNA N-glycosidase. The oligosaccharide is linked to the protein through an N-glycosidic bond, beta-GlcNAc-(1-N)-Asn51, and stretches from the surface of the N-terminal domain far from the active site, which suggests that it should not play a role in enzymatic function. The oligosaccharide of each beta-momorcharin molecule interacts with the protein through hydrogen bonds, although in the crystals most of these are intermolecular interactions with the protein atoms in an adjacent unit cell. This is the first example of an RIP structure which provides information about the three-dimensional structure and binding site of the oligosaccharide in the active chains of RIPs. |
==About this Structure== | ==About this Structure== | ||
| - | 1CF5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Momordica_charantia Momordica charantia]. Full crystallographic information is available from [http:// | + | 1CF5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Momordica_charantia Momordica charantia]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CF5 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Momordica charantia]] | [[Category: Momordica charantia]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: He, Y | + | [[Category: He, Y N.]] |
| - | [[Category: Xia, Z | + | [[Category: Xia, Z X.]] |
| - | [[Category: Xiong, J | + | [[Category: Xiong, J P.]] |
| - | [[Category: Yuan, Y | + | [[Category: Yuan, Y R.]] |
[[Category: glycoprotein]] | [[Category: glycoprotein]] | ||
[[Category: ribosome-inactivating protein]] | [[Category: ribosome-inactivating protein]] | ||
[[Category: rna n-glycosidase activity]] | [[Category: rna n-glycosidase activity]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:05:29 2008'' |
Revision as of 10:05, 21 February 2008
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BETA-MOMORCHARIN STRUCTURE AT 2.55 A
Overview
Beta-Momorcharin (Mr approximately 29 kDa) is a single-chained ribosome-inactivating protein (RIP) with a branched hexasaccharide bound to Asn51. The crystal structure of beta-momorcharin has been determined using the molecular-replacement method and refined to 2. 55 A resolution. The final structural model gave an R factor of 17. 2% and root-mean-square deviations of 0.016 A and 1.76 degrees from ideal bond lengths and bond angles, respectively. beta-Momorcharin contains nine alpha-helices, two 310 helices and three beta-sheets, and its overall structure is similar to those of other single-chained RIPs. Residues Tyr70, Tyr109, Glu158 and Arg161 are expected to define the active site of beta-momorcharin as an rRNA N-glycosidase. The oligosaccharide is linked to the protein through an N-glycosidic bond, beta-GlcNAc-(1-N)-Asn51, and stretches from the surface of the N-terminal domain far from the active site, which suggests that it should not play a role in enzymatic function. The oligosaccharide of each beta-momorcharin molecule interacts with the protein through hydrogen bonds, although in the crystals most of these are intermolecular interactions with the protein atoms in an adjacent unit cell. This is the first example of an RIP structure which provides information about the three-dimensional structure and binding site of the oligosaccharide in the active chains of RIPs.
About this Structure
1CF5 is a Single protein structure of sequence from Momordica charantia. Full crystallographic information is available from OCA.
Reference
Three-dimensional structure of beta-momorcharin at 2.55 A resolution., Yuan YR, He YN, Xiong JP, Xia ZX, Acta Crystallogr D Biol Crystallogr. 1999 Jun;55(Pt 6):1144-51. PMID:10329776
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