FIGURE 2.

Multiple sequence alignment. Shown is a partial multiple sequence alignment (ClustalX) of [FeFe]-hydrogenases from C. pasteurianum (Cp), D. desulfuricans (Dd), Chlamydomonas reinhardtii (Cr), Thermotoga maritima (Tm), Trichomonas vaginalis (Tv), S. oneidensis (So), and Neocallimastix frontalis (Nf). Amino acids predicted to participate in proton transfer are denoted by asterisks. Strictly conserved residues are indicated by black boxes, whereas highly conserved residues are in boldface. Residues with low conservation but chemically similar side chains are boxed. Every tenth amino acid of the C. pasteurianum sequence is denoted by a black dot. A multiple sequence alignment with 63 amino acid sequences can be found in supplemental Fig. 1.