Figure 1

Multiple Sequence Alignment of Rad60-Esc2-NIP45 (RENi) members. The alignment is CLUSTAL colored [44]. The organism from which a sequence has been derived is indicated by a 2 letter code preceding the database accession numbers: An Aspergillus nidulans, Ag Anopheles gambiae, At Arabidopsis thaliana, Ce Caenorhabditis elegans, Dd Dictyostelium discoideum, Dm Drosophila melanogaster, Gz Gibberella zeae, Hs Homo sapiens, Mm Mus musculus, Os Oryza sativa, Sc Saccharomyces cerevisiae, Sp Schizosaccharomyces pombe, Xl Xenopus laevis, Zm Zea mays. All accession numbers can be found in the NCBI non-redundant database, except 1) the ones of Xl, Zm and Os, which correspond to the TIGR Contig identifiers from which a presumptive translation was derived 2) the Dd protein which is included in the Sanger protein set with the accession JC3V1_0C0008_11033 3) the Ag protein was derived using FGENESH on a segment from Anopheles gambiae str. PEST chromosome 2L (accession AAAB01008810) 4) IL2N, 1A5R are entries from the PDB. The two alignment blocks correspond to the two distinct SUMO-like domains in RENi proteins. Only the second block includes plant representatives, which seem to miss the first SUMO-like domain. The SUMO sequences IL2N, 1A5R have been aligned to both blocks and the secondary structure elements below the alignment are derived from the PDBsum entries for both of these. Triangles mark positions reported to be involved in maintaining the ubiquitin-fold of human SUMO-1 [21]. These are also highlighted in the structural representation in Figure 2. Black encycled red-colored residues in NP_595995 point at the mutations in the rad60-1 (K263E) [15] and rad60-3 (F272V) [20] variants.