>4a73B (B:) observed residues (from ATOM records)
mkvgivgsgmvgsatayalallgvarevvlvdldrklaqahaedilhatpfahpvwvrag
sygdlegaravvlaagvaqrpgetrqlldrnaqvfaqvvprvleaapeavllvatnpvdv
mtqvayrlsglppgrvvgsgtildtarfrallaeylrvapqsvhayvlgehgdsevlvws
saqvggvpllefaeargaalspedraridegvrraayriiegkgatyygigaglarlvra
iltdekgvytvsaftpevegvlevslslprilgaggvegtvypslspeerealrrsaeil
keaafalgf