{{Short description|Enzyme}} {{infobox enzyme | Name = Alternansucrase | EC_number = 2.4.1.140 | CAS_number = 100630-46-4 | GO_code = | image = 5o8l.jpg | width = 270 | caption = Alternansucrase (dextransucrase) monomer, Leuconostoc citreum }} In enzymology, an '''alternansucrase''' ({{EC number|2.4.1.140}}) is an enzyme that catalyzes a chemical reaction that transfers an alpha-D-glucosyl residue from sucrose alternately to the 6- and 3-positions of the non-reducing terminal residue of an alpha-D-glucan, thereby creating a glucan with alternating alpha-1,6- and alpha-1,3-bonds. The name "alternan" was coined in 1982 (Cote & Robyt) for the glucan based on its alternating linkage structure.
This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is '''sucrose:1,6(1,3)-alpha-D-glucan 6(3)-alpha-D-glucosyltransferase'''. Other names in common use include '''sucrose-1,6(3)-alpha-glucan 6(3)-alpha-glucosyltransferase''', '''sucrose:1,6-, 1,3-alpha-D-glucan 3-alpha-''' and '''6-alpha-D-glucosyltransferase'''.
==References== {{reflist|1}} * {{cite journal |vauthors=Cote GL, Robyt JF | date = 1982 | title = Isolation and partial characterization of an extracellular glucansucrase from ''Leuconostoc mesenteroides'' NRRL B-1355 that synthesizes an alternating (1→6), (1→3)-α-<small>D</small>-glucan | journal = Carbohydr. Res. | volume = 101 | pages = 57–74 | pmid = 7060056 | doi = 10.1016/S0008-6215(00)80795-8 | issue = 1 }}
{{Glycosyltransferases}} {{Enzymes}} {{Portal bar|Biology|border=no}}
Category:EC 2.4.1 Category:Enzymes of unknown structure
{{2.4-enzyme-stub}}