Sugar isomerase (SIS) (IPR001347)

Short name: SIS

Overlapping homologous superfamilies


Domain relationships


The sugar isomerase (SIS) domain is a phosphosugar-binding module that is found in a variety of eubacterial, archaebacterial and eukaryotic proteins that have a role in phosphosugar isomerization or regulation [PMID: 10203754]. In enzymes, the SIS domain can have a catalytic function as an isomerase and bind to phosphorylated sugars. In bacterial transcriptional regulators of the rpiR family, the domain seems to bind substrates implicated in the genes for sugar metabolism that are controlled by the regulator. The SIS domain is found in one or two copies and can be linked to additional domains, such as helix-turn-helix (HTH), CBS, glutamine amidotransferases type 2, or phosphopantetheine-attachment [PMID: 10203754, PMID: 18049859].

The SIS domain has an alpha-beta structure and is dominated by a five-stranded parallel beta sheet flanked on either side by alpha helices forming a three- layer alpha-beta-alpha sandwich [PMID: 9739095]. The fold shows similarities to that of glucose-6-phosphate isomerase.

GO terms

Biological Process

GO:1901135 carbohydrate derivative metabolic process

Molecular Function

GO:0097367 carbohydrate derivative binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles