Wikipedia agrees quaternary structure quaternary structure English trimer Wikipedia agrees http://en.wikipedia.org/wiki/Protein_quaternary_structure English English Wikipedia agrees complete protein complete protein Protein quaternary structure English Wikipedia agrees complete protein http://en.wikipedia.org/wiki/Protein_quaternary_structure complete protein English Wikipedia agrees complete protein Wikipedia agrees hexamer English Wikipedia agrees quaternary structure quaternary structure quaternary structure English English Wikipedia agrees quaternary structure complete protein English hexamer Wikipedia agrees complete protein hexamer trimer trimer