View source for 2pc8

[[Image:2pc8.jpg|left|200px]]

 {{Structure
|PDB= 2pc8 |SIZE=350|CAPTION= <scene name='initialview01'>2pc8</scene>, resolution 1.800&Aring;
|SITE= <scene name='pdbsite=AC1:Bgc+Binding+Site+For+Residue+A+401'>AC1</scene> and <scene name='pdbsite=AC2:Bgc+Binding+Site+For+Residue+A+402'>AC2</scene>
|LIGAND= <scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>
|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Glucan_1,3-beta-glucosidase Glucan 1,3-beta-glucosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.58 3.2.1.58] </span>
|GENE= XOG1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=5476 Candida albicans])
|DOMAIN=<span class='plainlinks'>[http://www.ncbi.nlm.nih.gov/Structure/cdd/cddsrv.cgi?uid=pfam00150 Cellulase], [http://www.ncbi.nlm.nih.gov/Structure/cdd/cddsrv.cgi?uid=COG2730 BglC]</span>
|RELATEDENTRY=[[1eqp|1EQP]], [[1eqc|1EQC]], [[2pb1|2PB1]], [[2pbo|2PBO]]
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2pc8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2pc8 OCA], [http://www.ebi.ac.uk/pdbsum/2pc8 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2pc8 RCSB]</span>
}}

'''E292Q mutant of EXO-B-(1,3)-Glucanase from Candida Albicans in complex with two separately bound glucopyranoside units at 1.8 A'''


==Overview==
A group of fungal exo-beta-(1,3)-glucanases, including that from the human pathogen Candida albicans (Exg), belong to glycosyl hydrolase family 5 that also includes many bacterial cellulases (endo-beta-1, 4-glucanases). Family members, despite wide sequence variations, share a common mechanism and are characterised by possessing eight invariant residues making up the active site. These include two glutamate residues acting as nucleophile and acid/base, respectively. Exg is an abundant secreted enzyme possessing both hydrolase and transferase activity consistent with a role in cell wall glucan metabolism and possibly morphogenesis. The structures of Exg in both free and inhibited forms have been determined to 1.9 A resolution. A distorted (beta/alpha)8 barrel structure accommodates an active site which is located within a deep pocket, formed when extended loop regions close off a cellulase-like groove. Structural analysis of a covalently bound mechanism-based inhibitor (2-fluoroglucosylpyranoside) and of a transition-state analogue (castanospermine) has identified the binding interactions at the -1 glucose binding site. In particular the carboxylate of Glu27 serves a dominant hydrogen-bonding role. Access by a 1,3-glucan chain to the pocket in Exg can be understood in terms of a change in conformation of the terminal glucose residue from chair to twisted boat. The geometry of the pocket is not, however, well suited for cleavage of 1,4-glycosidic linkages. A second glucose site was identified at the entrance to the pocket, sandwiched between two antiparallel phenylalanine side-chains. This aromatic entrance-way must not only direct substrate into the pocket but also may act as a clamp for an acceptor molecule participating in the transfer reaction.

==About this Structure==
2PC8 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Candida_albicans Candida albicans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PC8 OCA]. 

==Reference==
The structure of the exo-beta-(1,3)-glucanase from Candida albicans in native and bound forms: relationship between a pocket and groove in family 5 glycosyl hydrolases., Cutfield SM, Davies GJ, Murshudov G, Anderson BF, Moody PC, Sullivan PA, Cutfield JF, J Mol Biol. 1999 Dec 3;294(3):771-83. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10610795 10610795]
[[Category: Candida albicans]]
[[Category: Glucan 1,3-beta-glucosidase]]
[[Category: Single protein]]
[[Category: Cutfield, J F.]]
[[Category: Cutfield, S M.]]
[[Category: Patrick, W M.]]
[[Category: additional ch binding site]]
[[Category: candida albican]]
[[Category: carbohydrate binding]]
[[Category: exo-glucanase]]
[[Category: hydrolase]]

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