1nbc
From Proteopedia
(New page: 200px<br /><applet load="1nbc" size="450" color="white" frame="true" align="right" spinBox="true" caption="1nbc, resolution 1.75Å" /> '''BACTERIAL TYPE 3A CE...) |
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| - | [[Image:1nbc.gif|left|200px]]<br /><applet load="1nbc" size=" | + | [[Image:1nbc.gif|left|200px]]<br /><applet load="1nbc" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1nbc, resolution 1.75Å" /> | caption="1nbc, resolution 1.75Å" /> | ||
'''BACTERIAL TYPE 3A CELLULOSE-BINDING DOMAIN'''<br /> | '''BACTERIAL TYPE 3A CELLULOSE-BINDING DOMAIN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of a family-III cellulose-binding domain (CBD) from | + | The crystal structure of a family-III cellulose-binding domain (CBD) from the cellulosomal scaffoldin subunit of Clostridium thermocellum has been determined at 1.75 A resolution. The protein forms a nine-stranded beta sandwich with a jelly roll topology and binds a calcium ion. conserved, surface-exposed residues map into two defined surfaces located on opposite sides of the molecule. One of these faces is dominated by a planar linear strip of aromatic and polar residues which are proposed to interact with crystalline cellulose. The other conserved residues are contained in a shallow groove, the function of which is currently unknown, and which has not been observed previously in other families of CBDs. On the basis of modeling studies combined with comparisons of recently determined NMR structures for other CBDs, a general model for the binding of CBDs to cellulose is presented. Although the proposed binding of the CBD to cellulose is essentially a surface interaction, specific types and combinations of amino acids appear to interact selectively with glucose moieties positioned on three adjacent chains of the cellulose surface. The major interaction is characterized by the planar strip of aromatic residues, which align along one of the chains. In addition, polar amino acid residues are proposed to anchor the CBD molecule to two other adjacent chains of crystalline cellulose. |
==About this Structure== | ==About this Structure== | ||
| - | 1NBC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Clostridium_thermocellum Clostridium thermocellum] with CA as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1NBC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Clostridium_thermocellum Clostridium thermocellum] with <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NBC OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Lamed, R.]] | [[Category: Lamed, R.]] | ||
| - | [[Category: Steitz, T | + | [[Category: Steitz, T A.]] |
[[Category: Tormo, J.]] | [[Category: Tormo, J.]] | ||
[[Category: CA]] | [[Category: CA]] | ||
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[[Category: scafoldin]] | [[Category: scafoldin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:04:20 2008'' |
Revision as of 12:04, 21 February 2008
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BACTERIAL TYPE 3A CELLULOSE-BINDING DOMAIN
Overview
The crystal structure of a family-III cellulose-binding domain (CBD) from the cellulosomal scaffoldin subunit of Clostridium thermocellum has been determined at 1.75 A resolution. The protein forms a nine-stranded beta sandwich with a jelly roll topology and binds a calcium ion. conserved, surface-exposed residues map into two defined surfaces located on opposite sides of the molecule. One of these faces is dominated by a planar linear strip of aromatic and polar residues which are proposed to interact with crystalline cellulose. The other conserved residues are contained in a shallow groove, the function of which is currently unknown, and which has not been observed previously in other families of CBDs. On the basis of modeling studies combined with comparisons of recently determined NMR structures for other CBDs, a general model for the binding of CBDs to cellulose is presented. Although the proposed binding of the CBD to cellulose is essentially a surface interaction, specific types and combinations of amino acids appear to interact selectively with glucose moieties positioned on three adjacent chains of the cellulose surface. The major interaction is characterized by the planar strip of aromatic residues, which align along one of the chains. In addition, polar amino acid residues are proposed to anchor the CBD molecule to two other adjacent chains of crystalline cellulose.
About this Structure
1NBC is a Single protein structure of sequence from Clostridium thermocellum with as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure of a bacterial family-III cellulose-binding domain: a general mechanism for attachment to cellulose., Tormo J, Lamed R, Chirino AJ, Morag E, Bayer EA, Shoham Y, Steitz TA, EMBO J. 1996 Nov 1;15(21):5739-51. PMID:8918451
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