>3bt2U (U:) observed residues (from ATOM records)
slrcmqcktngdcrveecalgqdlcrttivrlweegeelelvekscthsektnrtlsyrt
glkitsltevvcgldlcnqgnysrsryleciscgssdmscergrhqslqcrspeeqcldv
vthwikddrhlrgcgylpgcpgsngfhnndtfhflkccnttkcnegpilelenlpqngrq
cysckgnsthgcsseetflidcrgpmnqclvatgthepknqsymvrgcatasmcqlgdaf
smnhidvscctksgcnhpd