spacer
View the latest EBI news stories and important announcements...
more

spacer
Search The CSA
PDB ID
UNIPROT ID
EC Number

Catalytic Site Atlas

CSA LITERATURE entry for 1kdg

E.C. namecellobiose dehydrogenase (acceptor)
SpeciesPhanerochaete chrysosporium ()
E.C. Number (IntEnz) 1.1.99.18
CSA Homologues of 1kdgThere are 29 Homologs
CSA Entries With UniProtID Q01738
CSA Entries With EC Number 1.1.99.18
PDBe Entry 1kdg
PDBSum Entry 1kdg
MACiE Entry 1kdg

Literature Report

IntroductionFungal cellobiose dehydrogenase participates in the rotting of wood by catalysing a key step in the breakdown of cellulose, namely the oxidation of cellobiose to cellolactone. It shows sequence and structural homology with glucose and cholesterol oxidase, two other known enzymes catalysing similar processes, so the mechanism is likely to be the same between the three. FAD is used as a cofactor for the reaction, being reduced by the substrate and subsequently reoxidised by a cytochromal haem group contained in the non-active site containing domain (pdb 1d7b)
MechansimThe reaction is most likely to proceed through hydride transfer directly from the anomeric carbon on the reducing end of cellulobiose to FAD. This is facilitated by deprotonation of the anomeric carbon's OH group by a His 689 residue, assisted by Asn 732 resulting in the formation of the carbonyl group of cellolactone. The proton is then passed from the His 689 to a conserved water molecule which interacts with the pi bonding delocalised electrons of Tyr 609 to allow stabilisation of the H3O+ species.
Reaction

Catalytic Sites for 1kdg

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
HisA689707macie:sideChainActs as the general base to accept a proton from the anomeric carbon's OH group allowing the formation of the carbonyl.
AsnA732750macie:sideChainForms a hydrogen bond to the oxygen of the anomeric carbon's OH group thus assisting in the deprotonation at that site.

Annotated By Reference To The Literature - Site 2 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
HisB689707macie:sideChainActs as the general base to accept a proton from the anomeric carbon's OH group allowing the formation of the carbonyl.
AsnB732750macie:sideChainForms a hydrogen bond to the oxygen of the anomeric carbon's OH group thus assisting in the deprotonation at that site.

Literature References

Notes:
Hallberg BM
Mechanism of the reductive half-reaction in cellobiose dehydrogenase.
J Biol Chem 2003 278 7160-7166
PubMed: 12493734
spacer
spacer