Joint Center for Structural Genomics, Bioinformatics Core, University of California San Diego, La Jolla, California, USA.|Joint Center for Structural Genomics, Bioinformatics Core, University of California San Diego, La Jolla, California, USA.|Joint Center for Structural Genomics, Bioinformatics Core, University of California San Diego, La Jolla, California, USA.|Joint Center for Structural Genomics, Bioinformatics Core, University of California San Diego, La Jolla, California, USA.|Joint Center for Structural Genomics, Bioinformatics Core, University of California San Diego, La Jolla, California, USA.