Positively regulates the transcription of the maltose regulon whose gene products are responsible for uptake and catabolism of malto-oligosaccharides (PubMed:7040340, PubMed:3305511, PubMed:2538630, PubMed:2524384). Specifically binds to the promoter region of its target genes, recognizing a short DNA motif called the MalT box (5'-GGA[TG]GA-3') (PubMed:2538630, PubMed:2524384). Displays weak ATPase activity, but this activity is not required for promoter binding (PubMed:2524384). Activated by ATP and maltotriose, which are both required for DNA binding (PubMed:3305511, PubMed:2524384). Negatively regulated by MalY, MalK and Aes, which bind to MalT and block maltotriose activation (PubMed:9822819, PubMed:10692154, PubMed:11867639). Monomer in solution (PubMed:3305511, PubMed:10559195). Oligomerizes to an active state in the presence of the positive effectors ATP and maltotriose (PubMed:10559195). Interacts with MalY, MalK and Aes, all of which negatively regulate MalT activity by antagonizing maltotriose binding (PubMed:9822819, PubMed:10692154, PubMed:11867639). Expression is induced by the cAMP-activated global transcriptional regulator CRP. Consists of four structural domains: the ATP binding site resides in domain I (DT1); DT3 binds the positive effector maltotriose with a low affinity, and the binding affinity is increased in the presence of DT2; the C-terminal domain DT4 contains the helix-turn-helix DNA binding motif. DT1 also contains the region that interacts with MalY (but not with MalK), and the binding site for Aes is also likely to be contained in the N-terminal portion of MalT encompassing DT1 and DT2 (PubMed:12003949). Domain DT3 may mediate oligomerization (PubMed:11709169). A study on malT mutants has shown that some of them became nearly completely resistant to Aes repression while still being sensitive to MalY. These mutations are located at positions 38, 220, 243, and 359, most likely defining the interaction patch with Aes on the three-dimensional structure of MalT. Belongs to the MalT family.