Chains and heterogens:
PDB Chain Sequences:
>1exaA (A:) lspqleelitkvskahqetfpslcqlgkyttnssadhrvqldlglwdkfselatkciiki vefakrlpgftglsiadqitllkaacldilmlrictrytpeqdtmtfsdgltlnrtqmhn agfgpltdlvfafagqllplemddtetgllsaiclicgdrmdleepekvdklqeplleal rlyarrrrpsqpymfprmlmkitdlrgistkgaeraitlkmeipgpmppliremle