Chains and heterogens:
PDB Chain Sequences:
>1ir3A (A:) ssvfvpdewevsrekitllrelgqgsfgmvyegnardiikgeaetrvavktvnesaslre rieflneasvmkgftchhvvrllgvvskgqptlvvmelmahgdlksylrslrpeaennpg rppptlqemiqmaaeiadgmaylnakkfvhrdlaarncmvahdftvkigdfgmtrdiyet dyyrkggkgllpvrwmapeslkdgvfttssdmwsfgvvlweitslaeqpyqglsneqvlk fvmdggyldqpdncpervtdlmrmcwqfnpkmrptfleivnllkddlhpsfpevsffhse enk