e) Recombinant Atg5 was digested with calpain and the products sequenced by Edman degradation. Calpain cleaved Atg5 at Thr 193. Comparison of Atg5 sequences of different species demonstrates the presence of the same calpain cleavage site in mice. The sequence alignment was perfromed with Clustal W using sequence data obtained from GenBank. The position of the six-amino-acid deletion causing calpain resistance is indicated in red. 