SPX domain of proteins found in plants and stramenopiles; most have a C-terminal MFS domain
This region has been named the SPX domain after (Syg1, Pho81 and XPR1). The SPX domain is found at the amino terminus of a variety of proteins. This family, mostly found in plants, contains a C-terminal MFS domain (major facilitator superfamily), suggesting a function as a secondary transporter. The function of this N-terminal region is unclear, although it might be involved in regulating transport.