Chains and heterogens:
PDB Chain Sequences:
>1r3rA (A:) meanglgpqgfpelkndtflraawgeetdytpvwcmrqagrylpefretraaqdffstcr speacceltlqplrrfpldaaiifsnilvvpqalgmevtmvpgkgpsfpeplreeqdler lrdpevvaselgyvfqaitltrqrlagrvpligfagapwtlmtymvegggsstmaqakrw lyqrpqashqllriltdalvpylvgqvvagaqalqlfeshaghlgpqlfnkfalpyirdv akqvkarlreaglapvpmiifakdghfaleelaqagyevvgldwtvapkkarecvgktvt lqgnldpcalyaseeeigqlvkqmlddfgphryianlghglypdmdpehvgafvdavhkh srllrqn
>1r3rA (A:) fpelkndtflraawgeetdytpvwcmrqagrylpefretraaqdffstcrspeacceltl qplrrfpldaaiifsnilvvpqalgmevtmvpgkgpsfpeplreeqdlerlrdpevvase lgyvfqaitltrqrlagrvpligfagapwtlmtymvegggsstmaqakrwlyqrpqashq llriltdalvpylvgqvvagaqalqlfeshaghlgpqlfnkfalpyirdvakqvkarlre aglapvpmiifakdghfaleelaqagyevvgldwtvapkkarecvgktvtlqgnldpcal yaseeeigqlvkqmlddfgphryianlghglypdmdpehvgafvdavhkhsrllrq