SepL resembles an aberrant effector in binding to a class 1 type-III secretion chaperone and carrying an N-terminal secretion signal.

Here we show that the type-III secretion gatekeeper protein SepL resembles an aberrant effector protein, in binding to a class 1 type-III secretion chaperone (ORF12, here renamed CesL). We also show that short N-terminal fragments (≤70 amino acids) from SepL are capable of targeting fusion proteins for secretion and translocation.