ATP-binding (A) component of a common 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 including 5-formyltetrahydrofolate and thiamine. Expression of the complex plus FolT or ThiT in Lactococcus lactis subsp. cremoris (strain NZ9000) allows 5-formyltetrahydrofolate or thiamine uptake respectively; 5-formyltetrahydrofolate or thiamine are not taken up in the absence of FolT/ThiT or the EcfA1A2T complex. Deenergized L.lactis subsp. cremoris (treated with 2-deoxyglucose) does not take up substrate. Forms a stable energy-coupling factor (ECF) transporter complex probably composed of 2 membrane-embedded substrate-binding proteins (S component), 2 ATP-binding proteins (A component) and 2 transmembrane proteins (T component). This complex interacts with a number of substrate-specific components, including FolT and ThiT for 5-formyltetrahydrofolate and thiamine respectively. Belongs to the ABC transporter superfamily. Energy-coupling factor EcfA family.