ENZYME

ENZYME entry: EC 4.2.2.17

Accepted Name

Inulin fructotransferase (DFA-I-forming).

Alternative Name(s)

Inulin D-fructosyl-D-fructosyltransferase (1,2':1',2-dianhydride- forming).

Inulin D-fructosyl-D-fructosyltransferase (forming alpha-D-fructofuranose beta-D-fructofuranose 1,2':1',2-dianhydride).

Inulin fructotransferase (depolymerizing, difructofuranose-1,2':2',1- dianhydride-forming).

Inulin fructotransferase (DFA-I-producing).

Reaction catalysed

Produces alpha-D-fructofuranose beta-D-fructofuranose 1,2':2,1'-dianhydride (DFA I) by successively eliminating the diminishing (2->1)-beta-D-fructan (inulin) chain from the terminal D-fructosyl-D-fructosyl disaccharide

Comment(s)

This enzyme, like EC 4.2.2.16 and EC 4.2.2.18 eliminates the fructan chain from the terminal disaccharide leaving a difructose dianhydride.
These enzymes have long been known as fructotransferases, so this is retained in the description (official name).
Since the transfer is intramolecular, the reaction is an elimination and, hence, the enzyme is a lyase, belonging in enzyme class 4.-.-.-.
Formerly EC 2.4.1.200.

Cross-references

BRENDA

4.2.2.17

EC2PDB

4.2.2.17

ExplorEnz

4.2.2.17

PRIAM enzyme-specific profiles

4.2.2.17

KEGG Ligand Database for Enzyme Nomenclature

4.2.2.17

IUBMB Enzyme Nomenclature