EC	4.2.1.178
Accepted name:	difructose-dianhydride-III synthase
Reaction:	inulobiose = α-D-fructofuranose-β-D-fructofuranose 2′,1:2,3′-dianhydride + H2O
Glossary:	difructose anhydride III = α-D-fructofuranose-β-D-fructofuranose 2′,1:2,3′-dianhydride inulobiose = β-D-fructofuranosyl-(2→1)-D-fructose
Other name(s):	DFA-IIIase; difructose anhydride III hydrolase
Systematic name:	inulobiose hydro-lyase (α-D-fructofuranose-β-D-fructofuranose 2′,1:2,3′-dianhydride-forming)
Comments:	The enzyme participates in an inulin degradation pathway, in which it forms inulobiose from difructose anhydride III. A conformational change in the enzyme from the bacterium Pseudarthrobacter chlorophenolicus results in it also catalysing the activity of EC 4.2.2.18, inulin fructotransferase (DFA-III-forming).
References:	1.  Tanaka, T., Uchiyama, T., Kobori, H. and Tanaka, K. Enzymic hydrolysis of di-D-fructofuranose 1, 2′; 2, 3′ dianhydride with Arthrobacter ureafaciens. J. Biochem. 78 (1975) 1201–1206. [PMID: 1225919] 2.  Neubauer, A., Walter, M., and Buchholz, K. Formation of inulobiose from difructoseanhydride III catalysed by a lysate from Arthrobacter ureafaciens ATCC 21124. Biocatalysis and Biotransformation 18 (2000) 443–455. 3.  Saito, K., Sumita, Y., Nagasaka, Y., Tomita, F. and Yokota, A. Molecular cloning of the gene encoding the di-D-fructofuranose 1,2′:2,3′ dianhydride hydrolysis enzyme (DFA IIIase) from Arthrobacter sp. H65-7. J. Biosci. Bioeng. 95 (2003) 538–540. [PMID: 16233453] 4.  Yu, S., Wang, X., Zhang, T., Stressler, T., Fischer, L., Jiang, B. and Mu, W. Identification of a novel di-D-fructofuranose 1,2′:2,3′ dianhydride (DFA III) hydrolysis enzyme from Arthrobacter aurescens SK8.001. PLoS One 10:e0142640 (2015). [PMID: 26555784] 5.  Yu, S., Shen, H., Cheng, Y., Zhu, Y., Li, X., and Mu, W. Structural and functional basis of difructose anhydride III hydrolase, which sequentially converts inulin using the same catalytic residue. ACS Catalysis 8 (2018) 10683–10697.
[EC 4.2.1.178 created 2021]