Deaminates adenosine-37 to inosine in tRNA-Ala. adenosine(37) in tRNA(Ala) + H(+) + H2O = inosine(37) in tRNA(Ala) + NH4(+) Binds 1 myo-inositol hexakisphosphate (IP6) per subunit. Belongs to the ADAT1 family.