>1f21A (A:) observed residues (from ATOM records)
kqveiftdgsalgnpgpggygailryrgrektfsagytrttnnrmelmaaivalealkeh
aevilstdsqyvrqgitqwihnwkkrgwktadkkpvknvdlwqrldaalgqhqikwewvk
ghaghpeneradelaraaamnptledtgyqve