Include usually 12 but from time to time 14 transmembrane -helices (TMHs). For DtpT from Lactococcus

Contain ordinarily 12 but at times 14 transmembrane -helices (TMHs). For DtpT from Lactococcus lactis and human PEPT1 (hPEPT1), 12 TMHs have been verified experimentally (18, 19). The crystal structures…