>5l21A (A:) observed residues (from ATOM records)
gpmniintsilnlryesnhlidlsryaskinigskvnfdpidknqiqlfnlesskievil
knaivynsmyenfstsfwiripkyfnsislnneytiincmennsgwkvslnygeiiwtlq
dtqeikqrvvfkysqminisdyinrwifvtitnnrlnnskiyingrlidqkpisnlgnih
asnnimfkldgcrdthryiwikyfnlfdkelnekeikdlydnqsnsgilkdfwgdylqyd
kpyymlnlydpnkyvdvnnvgirgymylkgprgsvmttniylnsslyrgakfiikkynkd
nivrnndrvyinvvvknkeyrlatnasqagvekilsaleipdvgnlsqvvvmkskndqgi
tnkckmnlqdnngndigfigfhqfnniaklvasnwynrqierssrtlgcswefipvddgw
gerpl