Polysialic acid transport protein kpsD 558 kpsD MKLFKSILLIAACHAAQASAAIDINADPNLTGAAPLTGILNGQQSDTQNMSGFDNTPPPSPPVVMSRMFGAQLFNGTSADSGATVGFNPDYILNPGDSIQVRLWGAFTFDGALQVDPKGNIFLPNVGPVKVAGVSNSQLNALVTSKVKEVYQSNVNVYASLLQAQPVKVYVTGFVRNPGLYGGVTSDSLLNYLIKAGGVDPERGSYVDIVVKRGNRVRSNVNLYDFLLNGKLGLSQFADGDTIIVGPRQHTFSVQGDVFNSYDFEFRESSIPVTEALSWARPKPGATHITIMRKQGLQKRSEYYPISSAPGRMLQNGDTLIVSTDRYAGTIQVRVEGAHSGEHAMVLPYGSTMRAVLEKVRPNSMSQMNAVQLYRPSVAQRQKEMLNLSLQKLEEASLSAQSSTKEEASLRMQEAQLISRFVAKARTVVPKGEVILNESNIDSVLLEDGDVINIPEKTSLVMVHGEVLFPNAVSWQKGMTTEDYIEKCGGLTQKSGNARIIVIRQNGAAVNAEDVDSLKPGDEIMVLPKYESKNIEVTRGISTILYQLAVGAKVILSL KPSD1_ECOLX Involved in the translocation of the polysialic acid capsule across the outer membrane to the cell surface. May function as the periplasmic binding element of the PSA transport system, in which it transiently interacts with the membrane component of the transporter, binds polysaccharide and transports the polymer to a component in the outer membrane.