Chains and heterogens:
PDB Chain Sequences:
>1exfA (A:) vsaeeikkheekwnkyygvnafnlpkelfskvdekdrqkypyntignvfvkgqtsatgvl igkntvltnrhiakfangdpskvsfrpsintddngntetpygeyevkeilqepfgagvdl alirlkpdqngvslgdkispakigtsndlkdgdkleligypfdhkvnqmhrseielttls rglryygftvpgnsgsgifnsngelvgihsskvshldrehqinygvgignyvkriinekn e