Multiple sequence alignment of ribosomal protein S4. Shown is a representative sample of the full sequence alignment. Sequences are grouped according to specific sequence characteristics (see text) and positions are colored by conservation within the group at (blue) 95% and (red) 70%. The arrows above the alignment indicate positions of the two pairs of cysteine residues. The three-letter abbreviations indicate the phylum or class that the organisms belong to: ACD (Acidobacteria), ACT (Actinobacteria), ALP (Alphaproteobacteria), AQF (Aquificae), BAT (Bacteroidetes), BET (Betaproteobacteria), CHF (Chloroflexi), CHL (Chlamydiae), CHR (Chlorobi), CLT (Clostridia), CYN (Cyanobacteria), DEL (Deltaproteobacteria), DTH (Deinococcus-Thermus), EPS (Epsilonproteobacteria), FUS (Fusobacteria), GAM (Gammaproteobacteria), MAG (Magnetococcus), MOL (Mollicutes), PLN (Planctomycetes), SPR (Spirochaetes), VER (Verrucomicrobia).