>1xc4B (B:) observed residues (from ATOM records)
meryeslfaqlkerkegafvpfvtlgdpgieqslkiidtlieagadalelgipfvtpaqc
femlalirekhptipigllmyanlvfnkgidefyarcekvgvdsvlvadvpveesapfrq
aalrhnvapificppnadddllrqiasygrgytyllsragaalplnhlvaklkeynaapp
lqgfgisapdqvkaaidagaagaisgsaivkiieqhinepekmlaalkvfvqpmkaatrs