4D4B image
Entry Detail
PDB ID:
4D4B
Keywords:
Title:
The catalytic domain, BcGH76, of Bacillus circulans Aman6 in complex with MSMSMe
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2014-10-27
Release Date:
2015-03-25
Method Details:
Experimental Method:
Resolution:
1.30 Å
R-Value Free:
0.15
R-Value Work:
0.12
R-Value Observed:
0.12
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:ALPHA-1,6-MANNANASE
Mutations:YES
Chain IDs:A, B
Chain Length:362
Number of Molecules:2
Biological Source:BACILLUS CIRCULANS
Ligand Molecules
Primary Citation
Evidence for a Boat Conformation at the Transition State of Gh76 Alpha-1,6-Mannanases- Key Enzymes in Bacterial and Fungal Mannoprotein Metabolism
Angew.Chem.Int.Ed.Engl. 54 5378 ? (2015)
PMID: 25772148 DOI: 10.1002/ANIE.201410502

Abstact

α-Mannosidases and α-mannanases have attracted attention for the insight they provide into nucleophilic substitution at the hindered anomeric center of α-mannosides, and the potential of mannosidase inhibitors as cellular probes and therapeutic agents. We report the conformational itinerary of the family GH76 α-mannanases studied through structural analysis of the Michaelis complex and synthesis and evaluation of novel aza/imino sugar inhibitors. A Michaelis complex in an (O) S2 conformation, coupled with distortion of an azasugar in an inhibitor complex to a high energy B2,5 conformation are rationalized through ab initio QM/MM metadynamics that show how the enzyme surface restricts the conformational landscape of the substrate, rendering the B2,5 conformation the most energetically stable on-enzyme. We conclude that GH76 enzymes perform catalysis using an itinerary that passes through (O) S2 and B2,5 (≠) conformations, information that should inspire the development of new antifungal agents.

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