Structure and mechanism of D-xylose isomerase.
The action of xylose isomerase depends on the presence of two divalent cations. Crystal structure analyses of the free enzyme, and of the enzyme bound to a variety of substrates and inhibitors, have provided models for a number of distinct intermediates along the reaction pathway. These models, in turn, have suggested detailed mechanisms for the various chemical steps of the reaction: a ring opening catalysed by an activated histidine, a hydride-shift isomerization, and a ring closure which may be facilitated by a polarised water molecule.
Blow
D M
DM
Blackett Laboratory, Imperial College of Science Technology and Medicine, London, UK.
Collyer
C A
CA
Goldberg
J D
JD
Smart
O S
OS
D019747:Aldose-Ketose Isomerases; D001665:Binding Sites; D002238:Carbohydrate Epimerases / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation; D013329:Structure-Activity Relationship
D002238:Carbohydrate Epimerases; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase