Alignment of HydG sequences from T. vaginalis (Triva), C. reinhardtii (Chlre), Clostridium thermocellum (Cloth), and Bacteroides thetaiotaomicron (Bacth). A putative hydrogenosomal targeting sequence is shown in bold, and peptide sequences from hydrogenosomal protein spot S29 are shaded in gray. ▿, cysteine residues of the CXXXCXXC motif conserved in SAM-dependent proteins (30); *, conserved sites.