Chains and heterogens:
PDB Chain Sequences:
>1sz1A (A:) mkveeilekalelvipdeeevrkgreaeeelrrrldelgveyvfvgsyarntwlkgslei dvfllfpeefskeelrergleigkavldsyeiryaehpyvhgvvkgvevdvvpcyklkep kniksavdrtpfhhkwlegrikgkenevrllkgflkangiygaeykvrgfsgylcelliv fygsfletvknarrwtrrtvidvakgevrkgeeffvvdpvdekrnvaanlsldnlarfvh lcrefmeapslgffkpkhpleieperlrkiveergtavfavkfrkpdivddnlypqlera srkifeflerenfmplrsafkaseefcyllfecqikeisrvfrrmgpqfedernvkkfls rnrafrpfiengrwwafemrkfttpeegvrsyasthwhtlgknvgesireyfeiisgekl fkepvtaelcemmgvkd
>1sz1B (B:) mkveeilekalelvipdeeevrkgreaeeelrrrldelgveyvfvgsyarntwlkgslei dvfllfpeefskeelrergleigkavldsyeiryaehpyvhgvvkgvevdvvpcyklkep kniksavdrtpfhhkwlegrikgkenevrllkgflkangiygaeykvrgfsgylcelliv fygsfletvknarrwtrrtvidvakgevrkgeeffvvdpvdekrnvaanlsldnlarfvh lcrefmeapslgffkpkhpleieperlrkiveergtavfavkfrkpdivddnlypqlera srkifeflerenfmplrsafkaseefcyllfecqikeisrvfrrmgpqfedernvkkfls rnrafrpfiengrwwafemrkfttpeegvrsyasthwhtlgknvgesireyfeiisgekl fkepvtaelcemmgvkd