Dipeptide and tripeptide permease A (DtpA)-like subfamily of the Major Facilitator Superfamily of transporters
The DtpA-like subfamily includes four Escherichia coli proteins: dipeptide and tripeptide permeases A (DtpA, TppB or YdgR), B (DtpB or YhiP), C (DtpC or YjdL), and D (DtpD or YbgH). They are proton-dependent permeases that transport di- and tripeptides. DtpA and DtpB display a preference for di- and tripeptides composed of L-amino acids. DtpC shows higher specificity for dipeptides compared to tripeptides, and prefers dipeptides containing a C-terminal lysine residue. The DtpA-like subfamily belongs to the Major Facilitator Superfamily (MFS) of membrane transport proteins, which are thought to function through a single substrate binding site, alternating-access mechanism involving a rocker-switch type of movement.
Jiyao W et al.(2023). "The conserved domain database in 2023.",