We estimated the subsite structure of α-amylase II (TVA II) from Thermoactinomyces vulgaris R-47 expressed in Escherichia coli. TVA II has eight subsites, and the catalytic site is between the 5th and 6th subsite from the non-reducing end side. The subsite affinities, A-5, A-4, A-3, A-2, (A-1+A+1), A+2, and A+3, were calculated to be -0.35, 0.93, 0.55, 2.56, 1.18, 1.71, and 0.01 kcal mol-1, respectively.
