1gwk: Difference between revisions
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New page: left|200px<br /><applet load="1gwk" size="450" color="white" frame="true" align="right" spinBox="true" caption="1gwk, resolution 2.34Å" /> '''CARBOHYDRATE BINDING... |
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[[Image:1gwk.jpg|left|200px]]<br /><applet load="1gwk" size=" | [[Image:1gwk.jpg|left|200px]]<br /><applet load="1gwk" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1gwk, resolution 2.34Å" /> | caption="1gwk, resolution 2.34Å" /> | ||
'''CARBOHYDRATE BINDING MODULE FAMILY29'''<br /> | '''CARBOHYDRATE BINDING MODULE FAMILY29'''<br /> | ||
==Overview== | ==Overview== | ||
Carbohydrate-protein recognition is central to many biological processes. | Carbohydrate-protein recognition is central to many biological processes. Enzymes that act on polysaccharide substrates frequently contain noncatalytic domains, "carbohydrate-binding modules" (CBMs), that target the enzyme to the appropriate substrate. CBMs that recognize specific plant structural polysaccharides are often able to accommodate both the variable backbone and the side-chain decorations of heterogeneous ligands. "CBM29" modules, derived from a noncatalytic component of the Piromyces equi cellulase/hemicellulase complex, provide an example of this selective yet flexible recognition. They discriminate strongly against some polysaccharides while remaining relatively promiscuous toward both beta-1,4-linked manno- and cello-oligosaccharides. This feature may reflect preferential, but flexible, targeting toward glucomannans in the plant cell wall. The three-dimensional structure of CBM29-2 and its complexes with cello- and mannohexaose reveal a beta-jelly-roll topology, with an extended binding groove on the concave surface. The orientation of the aromatic residues complements the conformation of the target sugar polymer while accommodation of both manno- and gluco-configured oligo- and polysaccharides is conferred by virtue of the plasticity of the direct interactions from their axial and equatorial 2-hydroxyls, respectively. Such flexible ligand recognition targets the anaerobic fungal complex to a range of different components in the plant cell wall and thus plays a pivotal role in the highly efficient degradation of this composite structure by the microbial eukaryote. | ||
==About this Structure== | ==About this Structure== | ||
1GWK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Piromyces_equi Piromyces equi]. Full crystallographic information is available from [http:// | 1GWK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Piromyces_equi Piromyces equi]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GWK OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Piromyces equi]] | [[Category: Piromyces equi]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Charnock, S | [[Category: Charnock, S J.]] | ||
[[Category: Davies, G | [[Category: Davies, G J.]] | ||
[[Category: Nurizzo, D.]] | [[Category: Nurizzo, D.]] | ||
[[Category: carbohydrate binding domain]] | [[Category: carbohydrate binding domain]] | ||
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[[Category: mannohexaose]] | [[Category: mannohexaose]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:54:50 2008'' | ||