Multiple sequence alignments of novel candidate proteins. (a) A selenoprotein candidate from Geobacter sulfurreducens and its homologs. The possible selenocysteine residues are shown in red, and putative heme-binding motifs are underlined. Note that sequence conservation near the selenocysteine is comparable to that of the N-terminal cytochrome domain. A protein Dpro_2 contains yet another inframe stop codon (TAG) at the column 189. It will be either a sequencing error or a pseudogene. Gsul; G. sulfurreducens, Gmet; G. metallireducens, Gura; G. uraniumreducens, Gfrc; Geobacter sp. FRC-32, Dace; Desulfuromonas acetoxidans, Dpro; Delta proteobacterium MLMS-1. (b) Hypothetical proteins from Geobacter species. The inframe stop codons (TAG) are shown in red. This cluster is probably an artifact of close phylogenetic relationship.