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Catalytic Site Atlas

CSA LITERATURE entry for 2nlr

E.C. namecellulase
SpeciesStreptomyces lividans ()
E.C. Number (IntEnz)
CSA Homologues of 2nlrThere are 20 Homologs
CSA Entries With UniProtID
CSA Entries With EC Number
PDBe Entry 2nlr
PDBSum Entry 2nlr
MACiE Entry 2nlr

Literature Report

IntroductionThe glycosyl hydrolase family 12 member CelB is able to catalyse the breakdown of cellulose into glucose with retention of anomeric configuration. As a result, it is part of the endoglucanase clan GH-C which also includes the family 11 Xylanases, with a common fold and catalytic mechanism defining the clan.
MechansimThe reaction proceeds via a double displacement mechanism. Initial attack of the nucleophilic residue Glu 120 on the anomeric carbon of the beta-1-4-glycosidic bond results in cleavage of the bond, assisted by protonation of the leaving group at the 1C OH by Glu 203. This leads to a covalently bound enzyme intermediate, hydrolysis of which is achieved by a water molecule activated by deprotonation by Glu 203, releasing the products and regenerating the catalytically active forms of the nucleophilic and acid-base glutamates.

Catalytic Sites for 2nlr

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
GluA120160macie:sideChainActs as nucleophile to attack the anomeric carbon resulting in the formation of a covalently bound enzyme intermediate.

Literature References

Sulzenbacher G
The crystal structure of a 2-fluorocellotriosyl complex of the Streptomyces lividans endoglucanase CelB2 at 1.2 A resolution.
Biochemistry 1999 38 4826-4833
PubMed: 10200171