>1xl3B (B:) observed residues (from ATOM records)
arvsdveeqvnqylskvpeleqkqnvsellsllsnspnislsqlkaylegkseepseqfk
mlcglrdalkgrpelahlshlveqalvsmaeeqgetivlgaritpeayresqsgvnplqp
lrdtyrdavmgyqgiyaiwsdlqkrfpngdidsvilflqkalsadlqsqqsgsgreklgi
visdlqklkefgsvsdqvkgfwqffs