code: def get_seq_cluster(pdb_id_chain):
      
  
      url_root = 'http://www.rcsb.org/pdb/rest/sequenceCluster?structureId='
      out = get_info(pdb_id_chain, url_root = url_root)
      out = to_dict(out)
      return remove_at_sign(out['sequenceCluster'])
docs: Get the sequence cluster of a PDB ID plus a pdb_id plus a chain,
  
      Parameters
      ----------
  
      pdb_id_chain : string
          A string denoting a 4 character PDB ID plus a one character chain
          offset with a dot: XXXX.X, as in 2F5N.A
  
      Returns
      -------
  
      out : dict
          A dictionary containing the sequence cluster associated with the PDB
          entry and chain
  
      Examples
      --------
  
      >>> sclust = get_seq_cluster('2F5N.A')
      >>> print(sclust['pdbChain'][:10])
      [{'@name': '4PD2.A', '@rank': '1'},
       {'@name': '3U6P.A', '@rank': '2'},
       {'@name': '4PCZ.A', '@rank': '3'},
       {'@name': '3GPU.A', '@rank': '4'},
       {'@name': '3JR5.A', '@rank': '5'},
       {'@name': '3SAU.A', '@rank': '6'},
       {'@name': '3GQ4.A', '@rank': '7'},
       {'@name': '1R2Z.A', '@rank': '8'},
       {'@name': '3U6E.A', '@rank': '9'},
       {'@name': '2XZF.A', '@rank': '10'}]