Positively regulates the transcription of the maltose regulon whose gene products are responsible for uptake and catabolism of malto-oligosaccharides. Specifically binds to the promoter region of its target genes, recognizing a short DNA motif called the MalT box. Activated by ATP and maltotriose, which are both required for DNA binding. Monomer in solution. Oligomerizes to an active state in the presence of the positive effectors ATP and maltotriose. Belongs to the MalT family.