Joint Center for Structural Genomics, San Diego, USA. pnatarajan@sanfordburnham.org.|European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SD, UK. mpunta@ebi.ac.uk.|Joint Center for Structural Genomics, San Diego, USA. abhinavk@slac.stanford.edu.|Joint Center for Structural Genomics, San Diego, USA. Andrew.P.Yeh@gmail.com.|Joint Center for Structural Genomics, San Diego, USA. adam@sanfordburnham.org.|National Center for Biotechnology Information, National Library of Medicine, Building 38A, Bethesda, MD, 20894, USA. aravind@ncbi.nlm.nih.gov.