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Evry, June 27, 2011. ULB contribution to the MICROME Jamboree. Tools used for ULB contrib to MICROME. From the Regulatory Sequence Analysis Tools (RSAT, http://rsat.ulb.ac.be/rsat/ ). infer-operons : predict operons from genome annotations footprint-discovery
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Evry, June 27, 2011 ULB contribution to the MICROME Jamboree
Tools used for ULB contrib to MICROME • From the Regulatory Sequence Analysis Tools (RSAT, http://rsat.ulb.ac.be/rsat/). • infer-operons: predict operons from genome annotations • footprint-discovery • Gene-wise prediction of cis-regulatory elements by detecting conserved motifs in promoters of orthologous genes (phylogenetic footprints). • Inference of a co-regulation network by linking pairs of genes with similar footprints. • Network Analysis Tools (RSAT, http://rsat.ulb.ac.be/neat/). • pathway builder: extract a sub-network of a large metabolic networks (all reactions and compounds) that connects at best a set of seed nodes (e.g. enzymes in the same operon). • compare-classes: comparison between two files describung grouping of elements (e.g. genes) into sets (e.g. operon members), classes (e.g. GO), clusters (e.g. co-expression), etc ... • Pathway projection: comparison between annotated pathways and genome reaction content. • Patwhay comparison: comparison between predicted and annotated pathways.
Operon prediction • Example: Bacillus subtilis • http://rsat.ulb.ac.be/MICROME/results/operons/Bacillus_subtilis/Bacillus_subtilis_operons_inferred_dist55_2genes.html • We selected all the predicted operons containing at least 2 genes (single-gene transcription units are not reported).
Exercise: filling the gap • An operon from B.subtilis contains 4 enzyme-coding genes. • Those enzymes catalyze inter-connected reactions. • The pathway builder inferred 2 possible candidates as intermediates. • Can we use annotations to check the gap filling ?
Case study: purine operon(s) • The pur operon was splitted in 3 pieces by infer-operons, because some genes pairs have a larger spacing.
All METACYC pathways against genome-wise reaction sets • Results • http://rsat.ulb.ac.be/MICROME/results/pathway_projections/projection_against_metacyc/result_index.html • Tool: compare-classes • Approach: compare the set of all “possible” reactions in a given organism (enzyme-coding gene found in genome or spontaneous reaction) with all pathways annotated in Metacyc. • Stats: coverage + hypergeometric significance • Detailed output: lists of reactions found and missing for each pathway. • Example: Bacillus subtilis
Pathway projection profiles (D4.4) • Each row represents one pathway • Each column represents one organism • Separate sheets are generated to show the absolute and relative coverage, significance, ...
Pathway projection tree (D4.4) • The projections profiles can be mapped onto a taxonomic tree, using the tool GeneTrace (Victor Kunin and Christos Ouzounis). • Each intermediate node is annotated with the number of pathways found (green). • Each branch is annotated with the number of lost pathways (blue) or gained pathways (red).
Detection of conserved motifs in promoters of orthologs • Example of footprint-discovery result • http://rsat.ulb.ac.be/MICROME/results/footprints/Enterobacteriales/Escherichia_coli_K12/NP_416992.1/NP_416992.1_Escherichia_coli_K12_Enterobacteriales_ortho_dyads_3nt_sp0-20-2str-noov_taxfreq_sig0.png