1bvw
From Proteopedia
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| - | [[Image:1bvw.gif|left|200px]]<br /><applet load="1bvw" size=" | + | [[Image:1bvw.gif|left|200px]]<br /><applet load="1bvw" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1bvw, resolution 1.92Å" /> | caption="1bvw, resolution 1.92Å" /> | ||
'''CELLOBIOHYDROLASE II (CEL6A) FROM HUMICOLA INSOLENS'''<br /> | '''CELLOBIOHYDROLASE II (CEL6A) FROM HUMICOLA INSOLENS'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1BVW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Humicola_insolens Humicola insolens] with MAN, NAG, MG and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Cellulose_1,4-beta-cellobiosidase Cellulose 1,4-beta-cellobiosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.91 3.2.1.91] Known structural/functional Sites: <scene name='pdbsite=ACI:Catalytic Proton Donor (Experimental)'>ACI</scene>, <scene name='pdbsite=BAS:Catalytic Base (Proposed)'>BAS</scene> and <scene name='pdbsite=MOD:Pka Modulator'>MOD</scene>. Full crystallographic information is available from [http:// | + | 1BVW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Humicola_insolens Humicola insolens] with <scene name='pdbligand=MAN:'>MAN</scene>, <scene name='pdbligand=NAG:'>NAG</scene>, <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Cellulose_1,4-beta-cellobiosidase Cellulose 1,4-beta-cellobiosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.91 3.2.1.91] Known structural/functional Sites: <scene name='pdbsite=ACI:Catalytic+Proton+Donor+(Experimental)'>ACI</scene>, <scene name='pdbsite=BAS:Catalytic+Base+(Proposed)'>BAS</scene> and <scene name='pdbsite=MOD:Pka+Modulator'>MOD</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BVW OCA]. |
==Reference== | ==Reference== | ||
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[[Category: glycoside hydrolase family 6]] | [[Category: glycoside hydrolase family 6]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 09:34:04 2008'' |
Revision as of 07:34, 3 February 2008
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CELLOBIOHYDROLASE II (CEL6A) FROM HUMICOLA INSOLENS
Overview
The three-dimensional structure of the catalytic core of the family 6, cellobiohydrolase II, Cel6A (CBH II), from Humicola insolens has been, determined by X-ray crystallography at a resolution of 1.92 A. The, structure was solved by molecular replacement using the homologous, Trichoderma reesei CBH II as a search model. The H. insolens enzyme, displays a high degree of structural similarity with its T. reesei, equivalent. The structure features both O- (alpha-linked mannose) and, N-linked glycosylation and a hexa-co-ordinate Mg2+ ion. The active-site, residues are located within the enclosed tunnel that is typical for, cellobiohydrolase enzymes and which may permit a processive hydrolysis of, the cellulose substrate. The close structural similarity between the two, enzymes implies that kinetics and chain-end specificity experiments, performed on the H. insolens enzyme are likely to be applicable to the, homologous T. reesei enzyme. These cast doubt on the description of, cellobiohydrolases as exo-enzymes since they demonstrated that Cel6A (CBH, II) shows no requirement for non-reducing chain-ends, as had been, presumed. There is no crystallographic evidence in the present structure, to support a mechanism involving loop opening, yet preliminary modelling, experiments suggest that the active-site tunnel of Cel6A (CBH II) is too, narrow to permit entry of a fluorescenyl-derivatized substrate, known to, be a viable substrate for this enzyme.
About this Structure
1BVW is a Single protein structure of sequence from Humicola insolens with , , and as ligands. Active as Cellulose 1,4-beta-cellobiosidase, with EC number 3.2.1.91 Known structural/functional Sites: , and . Full crystallographic information is available from OCA.
Reference
Crystal structure of the catalytic core domain of the family 6 cellobiohydrolase II, Cel6A, from Humicola insolens, at 1.92 A resolution., Varrot A, Hastrup S, Schulein M, Davies GJ, Biochem J. 1999 Jan 15;337 ( Pt 2):297-304. PMID:9882628
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