Chains and heterogens:
PDB Chain Sequences:
>2cpkE (E:) vkeflakakedflkkwetpsqntaqldqfdriktlgtgsfgrvmlvkhkesgnhyamkil dkqkvvklkqiehtlnekrilqavnfpflvklefsfkdnsnlymvmeyvaggemfshlrr igrfsepharfyaaqivltfeylhsldliyrdlkpenllidqqgyiqvtdfgfakrvkgr twtlcgtpeylapeiilskgynkavdwwalgvliyemaagyppffadqpiqiyekivsgk vrfpshfssdlkdllrnllqvdltkrfgnlkngvndiknhkwfattdwiaiyqrkveapf ipkfkgpgdtsnfddyeeeeirvsinekcgkeftef