ATP-binding cassette component of polysaccharide transport system
The KpsT/Wzt ABC transporter subfamily is involved in extracellular polysaccharide export. Among the variety of membrane-linked or extracellular polysaccharides excreted by bacteria, only capsular polysaccharides, lipopolysaccharides, and teichoic acids have been shown to be exported by ABC transporters. A typical system is made of a conserved integral membrane and an ABC. In addition to these proteins, capsular polysaccharide exporter systems require two 'accessory' proteins to perform their function: a periplasmic (E.coli) or a lipid-anchored outer membrane protein called OMA (Neisseria meningitidis and Haemophilus influenza) and a cytoplasmic membrane protein MPA2.