>3r50D (D:) observed residues (from ATOM records)
alqlaahsdarsgpvgsnggqfwsfrpvrplnkivlsfsgspdqtlnlisitfssnptdi
itvggvgpepltytetvnidgdiieisgmianykgynvirsikfttnkkeygpyganagt
pfnikipdgnkivgffgnsgwyvdaigayytak