Figure S2. Schematic representation of Mal transport and regulon.

(A) Maltodextrin transport across the outer and inner membranes via LamB (maltoporin) in the outer membrane, MalE (maltose-binding protein) in the periplasm and the maltose inner membrane transporters (MalF, G, K). Once in the cytoplasm, maltodextrin is metabolized by enzymes (MalP, Q, Z). (B) Organisation of mal genes and their regulation: crp (cAMP-binding protein, needed for the transcription of malT and the transport gene cluster) induces the expression of MalT (a transcriptional activator) which is then activated by maltotriose. Activated MalT (Ta) and also crp regulate the expression of the maltose operons. For our study, note that LamB and MalE are not co-transcribed in the same direction. The knock-out of LamB does not disturb the expression of MalE. mal genes involved in maltose transport are written in blue and mal genes involved in maltose degradation are written in green (23, 48).