National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, MD 20894, USA and.|National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, MD 20894, USA and.|Computational Biology Research Center, National Institute of Advanced Industrial Science and Technology, Koto-ku, Tokyo 135-0064, Japan.|National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, MD 20894, USA and.