Figure 5

A) Architectural complexity plot of β-grasp domains found in eukaryotes and prokaryotes. The complexity quotient for a given species (y-axis) is plotted against the total number of β-grasp domain containing proteins in the same species. Names of species are given next to plot points. B) Domain architectures of β-grasp domains. Only a small sample of architectures is shown. These mainly represent novel or recently reported architectures that are described in the text. The TRS4 C-terminal domain, also found fused to certain E1-enzymes that lack the C-terminal UFD has a highly conserved ExxxH implying enzymatic function (see Additional file 1 for an alignment). Orange ellipses represent the conserved cysteine clusters observed in the NPL4-N family (see Additional file 1). A straight line with a small green box in the Ddi1 family architecture represents a possible cleavage site located between the domains. The proteins are not drawn to scale as only globular segments are show. Explanation of abbreviations/domain names: B3, DNA-binding domain; Auxin response, auxin-responsive transcription factor domain; OTU, OTU-like family of cysteine proteases; Znf, zinc-finger; Znf_LF, little finger family of zinc finger domains; R, Ring-finger domain; β-P, β-propeller domain; X, previously uncharacterized BofC C-terminal domain also found fused to a serine/threonine phosphatase in actinobacteria (see Additional file 1 for alignment). Organism abbreviations: Ehis, Entamoeba histolytica; Ath, Arabidopsis thaliana; Hsap, Homo sapiens; Rnor, Rattus norvegicus; Blic, Bacillus licheniformis; Mmaz, Methanosarcina mazei; Ddis, Dictyostelium discoideum; Lmaj, Leishmania major; Tcru, Trypanosoma cruzi; Pfal, Plasmodium falciparum; Tthe, Tetrahymena thermophila; Ncra, Neurospora crassa; Drer, Danio rerio; Cele, Caenorhabditis elegans; Dmel, Drosophila melonogaster; Scer, Saccharomyces cerevisiae; Tvag, Trichomonas vaginalis; Uma, Ustilago maydis; Spom, Schizosaccharomyces pombe; Cneo, Cryptococcus neoformans; Glam, Giardia lamblia; Cpar, Cryptosporidium parva; Tmar, Thermotoga maritima; Mpne, Mycoplasma pneumoniae; Ecol, Escherichia coli; Vcho, Vibrio cholerae; Hpyl, Helicobacter pylori; Nmen, Neisseria meningitides; Msp., Mesorhizobium sp.; Ctet, Clostridium tetani; Aaeo, Aquifex aeolicus; Tden, Treponema denticola; Drad, Deinococcus radiodurans; Mtub, Mycobacterium tuberculosis; Save, Streptomyces avermitilis; Bfra, Bacteroides fragilis; Ctep, Chlorobium tepidum; Nsp., Nostoc sp.; Ssp., Synecococcus sp.; Cpneu, Chlamydophila pneumoniae.