>1sz3B (B:) observed residues (from ATOM records)
mehderthvpvelraagvvllnergdillvqekgipekaglwhipsgavedgenpqdaav
reaceetglrvrpvkflgaylgrfpdgvlilrhvwlaepepgqtlapaftdeiaeasfvs
redfaqlyaagqirmyqtklfyadalrekgfpalp