title: Towards a comprehensive structural coverage of completed genomes: a structural genomics viewpoint.
abstract: BACKGROUND
  Structural genomics initiatives were established with the aim of solving protein structures on a large-scale. For many initiatives, such as the Protein Structure Initiative (PSI), the primary aim of target selection is focussed towards structurally characterising protein families which, so far, lack a structural representative. It is therefore of considerable interest to gain insights into the number and distribution of these families, and what efforts may be required to achieve a comprehensive structural coverage across all protein families.
  
  
  RESULTS
  In this analysis we have derived a comprehensive domain annotation of the genomes using CATH, Pfam-A and Newfam domain families. We consider what proportions of structurally uncharacterized families are accessible to high-throughput structural genomics pipelines, specifically those targeting families containing multiple prokaryotic orthologues. In measuring the domain coverage of the genomes, we show the benefits of selecting targets from both structurally uncharacterized domain families, whilst in addition, pursuing additional targets from large structurally characterised protein superfamilies.
  
  
  CONCLUSIONS
  This work suggests that such a combined approach to target selection is essential if structural genomics is to achieve a comprehensive structural coverage of the genomes, leading to greater insights into structure and the mechanisms that underlie protein evolution.
authors.affiliation: Department of Biochemistry and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK. marsden@biochem.ucl.ac.uk
authors.forename: Russell L
authors.initials: RL
authors.lastname: Marsden
authors.forename: Tony A
authors.initials: TA
authors.lastname: Lewis
authors.forename: Christine A
authors.initials: CA
authors.lastname: Orengo
mesh_terms: D000818:Animals; D030562:Databases, Protein; D016678:Genome / Q000235:genetics*; D023281:Genomics / Q000379:methods; D006801:Humans; D005810:Multigene Family; D020539:Sequence Analysis, Protein / Q000379:methods; D040681:Structural Homology, Protein