SIS (Sugar ISomerase) domains are found in many phosphosugar isomerases and phosphosugar binding proteins. SIS domains are also found in proteins that regulate the expression of genes involved in synthesis of phosphosugars. Presumably the SIS domains bind to the end-product of the pathway.

1: Involvement of the C terminus in intramolecular nitrogen channeling in glucosamine 6-phosphate synthase: evidence from a 1.6 A crystal structure of the isomerase domain. Teplyakov A, Obmolova G, Badet-Denisot MA, Badet B, Polikarpov I; Structure 1998;6:1047-1055. PMID:9739095

2: The SIS domain: a phosphosugar-binding domain. Bateman A; Trends Biochem Sci 1999;24:94-95. PMID:10203754