<p>The sugar transporters belong to a family of membrane proteins responsiblefor the transport of various sugars in a wide range of prokaryotic andeukaryotic organisms [<cite idref="PUB00005096"/>]. These integral membrane proteins arepredicted to comprise twelve membrane spanning domains. It is likely that thetransporters have evolved from an ancient protein present in living organismsbefore the divergence into prokaryotes and eukaryotes [<cite idref="PUB00003999"/>]. In mammals,these proteins are expressed in a number of organs [<cite idref="PUB00002464"/>]. Proteins transporting sugars and other substrates are related in this broader family.</p><p>Sialic acid transporters belong to this group.</p> Sialic acid transporter