Figure 2

Numbers of arCOGs in different functional categories (COG classification) lost or gained in the I. hospitalis lineage. The sets of lost and gained genes were derived on the basis of a comparison of the I. hospitalis gene compliment with the reconstructed gene set of the last common ancestor of Desulfurococcales [27] (see Additional data files). The numbers of arCOGs in each category that are present in N. equitans but are absent in I. hospitalis are also indicated. The one letter code for COG categories is the following: amino acid transport and metabolism (E); carbohydrate transport and metabolism (G); cell cycle control, cell division, chromosome partitioning (D); cell motility (N); cell wall/membrane/envelope biogenesis (M); coenzyme transport and metabolism (H); defense mechanisms (V); energy production and conversion (C); inorganic ion transport and metabolism (P); intracellular trafficking, secretion, and vesicular transport (U); lipid transport and metabolism (I); nucleotide transport and metabolism (F); posttranslational modification, protein turnover, chaperones (O); replication, recombination and repair (L); secondary metabolites biosynthesis, transport and catabolism (Q); signal transduction mechanisms (T); transcription (K); and translation, ribosomal structure and biogenesis (J).