>3stxB (B:) observed residues (from ATOM records)
spfvkkhfvlvhtafhgawcwykivalmrssghnvtaldlgasginpkqalqipnfsdyl
splmefmaslpanekiilvghalgglaiskametfpekisvavflsglmpgpnidattvc
tkagsavlgqldncvtyengptnppttliagpkflatnvyhlspiedlalatalvrplyl
ylaediskevvlsskrygsvkrvfivatenkkeflklmieknppdevkeiegsdavtmms
kpqqlfttllsiankyk