Department of Biochemistry, Program in Bioinformatics, Ann Arbor, MI 48109, USA. jfalkner@umich.edu|Department of Biochemistry, Program in Bioinformatics, Ann Arbor, MI 48109, USA. jfalkner@umich.edu|Department of Biochemistry, Program in Bioinformatics, Ann Arbor, MI 48109, USA. jfalkner@umich.edu