Folate-binding protein that interacts with the energy-coupling factor (ECF) ABC-transporter complex. Unlike classic ABC transporters this ECF transporter provides the energy necessary to transport a number of different substrates. The substrates themselves are bound by transmembrane, not extracytoplasmic soluble proteins (By similarity). Binds folic acid with a dissociation constant of 9 nM; binds polyglutamyl folates less well. Upon coexpression with its energy-coupling factor (ECF) ABC-transporter complex EcfA1A2T in Lactococcus lactis subsp. cremoris (strain NZ9000) allows high level 5-formyltetrahydrofolate uptake; uptake requires both FolT and EcfA1A2T. Low levels of uptake occur in the presence of FolT alone, perhaps because it interacts with endogenous EcfA1A2T. In Lactococcus lactis subsp. cremoris (strain NZ9000) forms a stable energy-coupling factor (ECF) transporter complex composed of a membrane-embedded substrate-binding protein (S component), two ATP-binding proteins (A components) and a transmembrane protein (T component) (Probable).