1. Department of Animal and Dairy Sciences, Program in Cell and Molecular Biosciences, Auburn University, Auburn, AL 36849-5415
2. Department of Biochemistry, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
3. Department of Molecular Biology, The University of Texas Health Science Center at Tyler, 11937 US Highway 271, Tyler, TX 75708-3154