Chains and heterogens:
PDB Chain Sequences:
>1ck4A (A:) cstqldivivldgsnsiypwesviaflndllkrmdigpkqtqvgivqygenvthefnlnk yssteevlvaankigrqgglqtmtalgidtarkeafteargarrgvkkvmvivtdgeshd nyrlkqviqdcedeniqrfsiailghynrgnlstekfveeiksiaseptekhffnvsdel alvtivkalgerifalea
>1ck4A (A:) tqldivivldgsnsiypwesviaflndllkrmdigpkqtqvgivqygenvthefnlnkys steevlvaankigrqgglqtmtalgidtarkeafteargarrgvkkvmvivtdgeshdny rlkqviqdcedeniqrfsiailghynrgnlstekfveeiksiaseptekhffnvsdelal vtivkalgerifa
>1ck4B (B:) cstqldivivldgsnsiypwesviaflndllkrmdigpkqtqvgivqygenvthefnlnk yssteevlvaankigrqgglqtmtalgidtarkeafteargarrgvkkvmvivtdgeshd nyrlkqviqdcedeniqrfsiailghynrgnlstekfveeiksiaseptekhffnvsdel alvtivkalgerifalea
>1ck4B (B:) tqldivivldgsnsiypwesviaflndllkrmdigpkqtqvgivqygenvthefnlnkys steevlvaankigrqgglqtmtalgidtarkeafteargarrgvkkvmvivtdgeshdny rlkqviqdcedeniqrfsiailghynrgnlstekfveeiksiaseptekhffnvsdelal vtivkalgerifale