Multiple sequence alignment of the Alba family was constructed using the T-Coffee program after parsing high-scoring pairs from PSI-BLAST search results. The alignment of the Alba superfamily is superimposed on the structure-based alignments with members of the IF3-C and YhbY superfamilies. The secondary structure, derived from the representatives of these superfamilies with available structures, is shown above the alignment, with E representing a β strand and H an α-helix. The box shows the shared loop, which is typically bounded by small residues in Alba and YhbY. The 95% consensus shown below each family was derived using the following amino acid classes: hydrophobic (h: ALICVMYFW, yellow shading) and their aliphatic subset (l: ILV, yellow shading); aromatic (a: FHWY, yellow shading); small (s: ACDGNPSTV, green) and their tiny subset (u: GAS, green shading); charged (c: DEHKR, pink) and their basic subset (+: HKR, pink) and acidic subset (-: DE, pink); and polar (p: CDEHKNQRST, blue) and their alcoholic subset (o: ST, blue). A 'G', 'K' or 'E' shows the completely conserved amino acid in that group. The position corresponding to the lysine, which is acetylated in Alba, is shown in red. The limits of the domains are indicated by the residue positions, on each end of the sequence. The 'R' to the right of the sequence denotes those members that have the RNA-binding 'RGG' repeats at the C terminus. The numbers within the alignment are non-conserved inserts that have not been shown. The sequences are denoted by their gene name followed by the species abbreviation and GeneBank Identifier. Species abbreviations are as follows: Af, Archaeoglobus fulgidus; Aga, Anopheles gambiae; Ana, Anabaena sp.; Ap, Aeropyrum pernix; At, Arabidopsis thaliana; Bsub, Bacillus subtilis; Cace, Clostridium acetobutylicum; Ce, Caenorhabditis elegans; Dm, Drosophila melanogaster; Ec, Escherichia coli; Fac, Ferroplasma acidarmanus; Gste, Geobacillus stearothermophilus; Hs, Homo sapiens; Linf, Leishmania infantum; Mjan, Methanococcus jannaschii; Mka, Methanopyrus kandleri; Mm, Mus musculus; Mta, Methanothermobacter thermautotrophicus; Nm, Neisseria meningitidis; Osa, Oryza sativa; Pa, Pyrococcus abyssi; Pfa, Plasmodium falciparum; Pfu, Pyrococcus furiosus; Ph, Pyrococcus horikoshii; Pyae, Pyrobaculum aerophilum; Pyo, Plasmodium yoelii; Rn, Rattus norvegicus; Sc, Saccharomyces cerevisiae; Slem, Stylonychia lemnae; Sp, Schizosaccharomyces pombe; Ssh, Sulfolobus shibatae; Sso, Sulfolobus solfataricus; Sst, Sulfolobus tokodaii; Tac, Thermoplasma acidophilum.