>1sr4B (B:) observed residues (from ATOM records)
nlsdfkvatwnlqgssavneskwninvrqllsgeqgadilmvqeagslpssavrtsrviq
hggtpieeytwnlgtrsrpnmvyiyysrldvganrvnlaivsrrqadeafivhsdssvlq
srpavgirigtdvfftvhalatggsdavslirnifttfnspperrvyswmvvgdfnrapa
nlevalrqepavsentiiiaptepthrsgnildyailhdahlprreqarerigaslmlnq
lrsqitsdhfpvsfvrdr