Chains and heterogens:
PDB Chain Sequences:
>1s4uX (X:) gplgspefpgmskvfiatanagkahdadifsvsacnsftvscsgdgylkvwdnklldnen pkdksyshfvhksglhhvdvlqaierdafelclvattsfsgdllfyritredetkkvife kldlldsdmkkhsfwalkwgasndrllshrlvatdvkgttyiwkfhpfadesnsltlnws ptlelqgtvespmtpsqfatsvdisergliatgfnngtvqiselstlrplynfesqhsmi nnsnsirsvkfspqgsllaiahdsnsfgcitlyetefgerigslsvpthssqaslgefah sswvmslsfndsgetlcsagwdgklrfwdvktkerittlnmhcddieieedilavdehgd slaepgvfdvkflkkgwrsgmgadlneslccvcldrsirwfreaggk
>1s4uX (X:) kvfiatanagkahdadifsvsacnsftvscsgdgylkvwdnklldnenpkdksyshfvhk sglhhvdvlqaierdafelclvattsfsgdllfyritrkkvifekldlldsdmkkhsfwa lkwgaslshrlvatdvkgttyiwkfhpfadesnsltlnwsptlelqgtvespmtpsqfat svdisergliatgfnngtvqiselstlrplynfensirsvkfspqgsllaiahdsnsfgc itlyetefgerigslsvfahsswvmslsfndsgetlcsagwdgklrfwdvktkerittln mhcddieieedilavdehgdslaepgvfdvkflkkgwrsneslccvcldrsirwfr