1c1f
From Proteopedia
(New page: 200px<br /><applet load="1c1f" size="450" color="white" frame="true" align="right" spinBox="true" caption="1c1f, resolution 1.60Å" /> '''LIGAND-FREE CONGERIN...) |
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| - | [[Image:1c1f.gif|left|200px]]<br /><applet load="1c1f" size=" | + | [[Image:1c1f.gif|left|200px]]<br /><applet load="1c1f" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1c1f, resolution 1.60Å" /> | caption="1c1f, resolution 1.60Å" /> | ||
'''LIGAND-FREE CONGERIN I'''<br /> | '''LIGAND-FREE CONGERIN I'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: Congerin I is a member of the galectin (animal | + | BACKGROUND: Congerin I is a member of the galectin (animal beta-galactoside-binding lectin) family and is found in the skin mucus of conger eel. The galectin family proteins perform a variety of biological activities. Because of its histological localization and activity against marine bacteria and starfish embryos, congerin I is thought to take part in the eels' biological defense system against parasites. RESULTS: The crystal structure of congerin I has been determined in both lactose-liganded and ligand-free forms to 1. 5 A and 1.6 A resolution, respectively. The protein is a homodimer of 15 kDa subunits. Congerin I has a beta-sheet topology that is markedly different from those of known relatives. One of the beta-strands is exchanged between two identical subunits. This strand swap might increase the dimer stability. Of the known galectin complexes, congerin I forms the most extensive interaction with lactose molecules. Most of these interactions are substituted by similar interactions with water molecules, including a pi-electron hydrogen bond, in the ligand-free form. This observation indicates an increased affinity of congerin I for the ligand. CONCLUSIONS: The genes for congerin I and an isoform, congerin II, are known to have evolved under positive selection pressure. The strand swap and the modification in the carbohydrate-binding site might enhance the cross-linking activity, and should be the most apparent consequence of positive selection. The protein has been adapted to functioning in skin mucus that is in direct contact with surrounding environments by an enhancement in cross-linking activity. The structure of congerin I demonstrates the emergence of a new structure class by accelerated evolution under selection pressure. |
==About this Structure== | ==About this Structure== | ||
| - | 1C1F is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Conger_myriaster Conger myriaster]. Full crystallographic information is available from [http:// | + | 1C1F is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Conger_myriaster Conger myriaster]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1C1F OCA]. |
==Reference== | ==Reference== | ||
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[[Category: lectin]] | [[Category: lectin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:01:21 2008'' |
Revision as of 10:01, 21 February 2008
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LIGAND-FREE CONGERIN I
Overview
BACKGROUND: Congerin I is a member of the galectin (animal beta-galactoside-binding lectin) family and is found in the skin mucus of conger eel. The galectin family proteins perform a variety of biological activities. Because of its histological localization and activity against marine bacteria and starfish embryos, congerin I is thought to take part in the eels' biological defense system against parasites. RESULTS: The crystal structure of congerin I has been determined in both lactose-liganded and ligand-free forms to 1. 5 A and 1.6 A resolution, respectively. The protein is a homodimer of 15 kDa subunits. Congerin I has a beta-sheet topology that is markedly different from those of known relatives. One of the beta-strands is exchanged between two identical subunits. This strand swap might increase the dimer stability. Of the known galectin complexes, congerin I forms the most extensive interaction with lactose molecules. Most of these interactions are substituted by similar interactions with water molecules, including a pi-electron hydrogen bond, in the ligand-free form. This observation indicates an increased affinity of congerin I for the ligand. CONCLUSIONS: The genes for congerin I and an isoform, congerin II, are known to have evolved under positive selection pressure. The strand swap and the modification in the carbohydrate-binding site might enhance the cross-linking activity, and should be the most apparent consequence of positive selection. The protein has been adapted to functioning in skin mucus that is in direct contact with surrounding environments by an enhancement in cross-linking activity. The structure of congerin I demonstrates the emergence of a new structure class by accelerated evolution under selection pressure.
About this Structure
1C1F is a Single protein structure of sequence from Conger myriaster. Full crystallographic information is available from OCA.
Reference
High-resolution structure of the conger eel galectin, congerin I, in lactose-liganded and ligand-free forms: emergence of a new structure class by accelerated evolution., Shirai T, Mitsuyama C, Niwa Y, Matsui Y, Hotta H, Yamane T, Kamiya H, Ishii C, Ogawa T, Muramoto K, Structure. 1999 Oct 15;7(10):1223-33. PMID:10545323
Page seeded by OCA on Thu Feb 21 12:01:21 2008
Categories: Conger myriaster | Single protein | Hotta, H. | Ishii, C. | Kamiya, H. | Matsui, Y. | Mitsuyama, C. | Muramoto, K. | Niwa, Y. | Ogawa, T. | Shirai, T. | Yamane, T. | Beta-galactose-binding | Galectin | Lectin
