1e7n
From Proteopedia
(New page: 200px<br /><applet load="1e7n" size="450" color="white" frame="true" align="right" spinBox="true" caption="1e7n, resolution 2.35Å" /> '''THE N-TERMINAL DOMAI...) |
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| - | [[Image:1e7n.jpg|left|200px]]<br /><applet load="1e7n" size=" | + | [[Image:1e7n.jpg|left|200px]]<br /><applet load="1e7n" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1e7n, resolution 2.35Å" /> | caption="1e7n, resolution 2.35Å" /> | ||
'''THE N-TERMINAL DOMAIN OF BETA-B2-CRYSTALLIN RESEMBLES THE PUTATIVE ANCESTRAL HOMODIMER'''<br /> | '''THE N-TERMINAL DOMAIN OF BETA-B2-CRYSTALLIN RESEMBLES THE PUTATIVE ANCESTRAL HOMODIMER'''<br /> | ||
==Overview== | ==Overview== | ||
| - | betagamma-crystallins from the eye lens are proteins consisting of two | + | betagamma-crystallins from the eye lens are proteins consisting of two similar domains joined by a short linker. All three-dimensional structures of native proteins solved so far reveal similar pseudo-2-fold pairing of the domains reflecting their presumed ancient origin from a single-domain homodimer. However, studies of engineered single domains of members of the betagamma-crystallin superfamily have not revealed a prototype ancestral solution homodimer. Here we report the 2.35 A X-ray structure of the homodimer of the N-terminal domain of rat betaB2-crystallin (betaB2-N). The two identical domains pair in a symmetrical manner very similar to that observed in native betagamma-crystallins, where N and C-terminal domains (which share approximately 35% sequence identity) are related by a pseudo-2-fold axis. betaB2-N thus resembles the ancestral prototype of the betagamma-crystallin superfamily as it self-associates in solution to form a dimer with an essentially identical domain interface as that between the N and C domains in betagamma-crystallins, but without the benefit of a covalent linker. The structure provides further evidence for the role of two-domain pairing in stabilising the protomer fold. These results support the view that the betagamma-crystallin superfamily has evolved by a series of gene duplication and fusion events from a single-domain ancestor capable of forming homodimers. |
==About this Structure== | ==About this Structure== | ||
| - | 1E7N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http:// | + | 1E7N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1E7N OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Basak, A.]] | [[Category: Basak, A.]] | ||
| - | [[Category: Bateman, O | + | [[Category: Bateman, O A.]] |
| - | [[Category: Clout, N | + | [[Category: Clout, N J.]] |
[[Category: Jaenicke, R.]] | [[Category: Jaenicke, R.]] | ||
[[Category: Slingsby, C.]] | [[Category: Slingsby, C.]] | ||
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[[Category: protein structure]] | [[Category: protein structure]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:24:50 2008'' |
Revision as of 10:24, 21 February 2008
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THE N-TERMINAL DOMAIN OF BETA-B2-CRYSTALLIN RESEMBLES THE PUTATIVE ANCESTRAL HOMODIMER
Overview
betagamma-crystallins from the eye lens are proteins consisting of two similar domains joined by a short linker. All three-dimensional structures of native proteins solved so far reveal similar pseudo-2-fold pairing of the domains reflecting their presumed ancient origin from a single-domain homodimer. However, studies of engineered single domains of members of the betagamma-crystallin superfamily have not revealed a prototype ancestral solution homodimer. Here we report the 2.35 A X-ray structure of the homodimer of the N-terminal domain of rat betaB2-crystallin (betaB2-N). The two identical domains pair in a symmetrical manner very similar to that observed in native betagamma-crystallins, where N and C-terminal domains (which share approximately 35% sequence identity) are related by a pseudo-2-fold axis. betaB2-N thus resembles the ancestral prototype of the betagamma-crystallin superfamily as it self-associates in solution to form a dimer with an essentially identical domain interface as that between the N and C domains in betagamma-crystallins, but without the benefit of a covalent linker. The structure provides further evidence for the role of two-domain pairing in stabilising the protomer fold. These results support the view that the betagamma-crystallin superfamily has evolved by a series of gene duplication and fusion events from a single-domain ancestor capable of forming homodimers.
About this Structure
1E7N is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.
Reference
The N-terminal domain of betaB2-crystallin resembles the putative ancestral homodimer., Clout NJ, Basak A, Wieligmann K, Bateman OA, Jaenicke R, Slingsby C, J Mol Biol. 2000 Dec 1;304(3):253-7. PMID:11090271
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