The Enzymes wiki is being developed, but some great sites to go to until it is complete are:
ExploreEnz, a simple enzyme database based on the IUBMB enzyme list.
Expasy, another simple enzyme database also based on the IUBMB enzyme list.
IntEnz, another simple enzyme database also based on the IUBMB enzyme list.
IUBMB, the IUBMB website.
KEGG enzyme, which is the enzyme part of the KEGG site, a very large and useful site.
CAZY, a smaller database focused on enzymes involving carbohydrates.
ThYme, a smaller database focused on enzymes involving thioesters.
Orphan, a smaller database focused on orphan enzymes.
MMEB, a smaller database focused on mammalian metabolic enzymes.
MEROPS, a smaller database focused on peptidases.
PDB, a large database covering all proteins (173k structures!).
Biocyc, a large, detailed database of enzymes, pathways and genomes of a number of organisms. Will be a real shame when this one disappears also.
Rhea reactions, a large database covering biochemical reactions and the enzymes and proteins associated with them.
Worthington Enzyme Manual,a company sponsored database of common enzymes and proteins.
Enzyme Finder, a database of restriction enzymes.
There used to be many more, but they are gone. The above links will probably not last long either so get as much as you can from them before they disappear.
links checked January 2021