Chains and heterogens:
PDB Chain Sequences:
>4xb3A (A:) mqkhwwhkatvyqiypksfmdtngdgigdlkgitskldylqklgvmaiwlspvydspmdd ngydianyeaiadifgnmadmdnlltqakmrgikiimdlvvnhtsdehawfiearehpds serdyyiwcdqpndlesifggsawqyddksdqyylhffskkqpdlnwenanlrqkiydmm nfwidkgiggfrmdvidmigkipaqhivsngpklhaylkemnaasfgqhdlltvgqtwga tpeiakqysnpvnhelsmvfqfehiglqhkpeapkwdyvkelnvpalktifnkwqtelel gqgwnslfwnnhdlprvlsiwgntgkyreksakalaillhlmrgtpyiyqgeeigmtnyp fkdlnelddieslnyakeaftngksmetimdsirmigrdnartpmqwdasqnagfstadk twlpvnpnykdinvqaalknsnsifytyqqliqlrkendwlvdadfellptadkvfaylr kvreerylivvnvsdqeevleidvdkqetlisntnesaalanhklqpwdafcikil