>2a21B (B:) SEQRES residues mekflviagpcaieseelllkvgeeikrlsekfkevefvfkssfdkanrssihsfrghgl eygvkalrkvkeefglkittdiheswqaepvaevadiiqipaflcrqtdlllaaaktgra vnvkkgqflapwdtknvveklkfggakeiyltergttfgynnlvvdfrslpimkqwakvi ydathsvqlpgglgdksggmrefifpliraavavgcdgvfmethpepekalsdastqlpl sqlegiieaileirevaskyyetipvk