lib/bio/db/pdb/chemicalcomponent.rb in bio-1.4.2 vs lib/bio/db/pdb/chemicalcomponent.rb in bio-1.4.3

@@ -3,11 +3,10 @@
 #
 # Copyright:: Copyright (C) 2006
 #             GOTO Naohisa <[e-mail]>
 # License::   The Ruby License
 #
-# $Id: chemicalcomponent.rb,v 1.3 2007/04/05 23:35:41 trevor Exp $
 #
 # = About Bio::PDB::ChemicalComponent
 #
 # Please refer Bio::PDB::ChemicalComponent.
 #
@@ -15,12 +14,14 @@
 #
 # * ((<URL:http://deposit.pdb.org/cc_dict_tut.html>))
 # * http://deposit.pdb.org/het_dictionary.txt
 #
 
-require 'bio/db/pdb/pdb'
 
 module Bio
+
+  require 'bio/db/pdb' unless const_defined?(:PDB)
+
   class PDB
 
     # Bio::PDB::ChemicalComponet is a parser for a entry of
     # the PDB Chemical Component Dictionary.
     #