Alignment of the amino acid sequences of TrxHEp homologues. Dots denote gaps introduced for maximum matching. The consensus residues are in black, the residues that are ≥ 75% identical among the aligned sequences are in pink. Conserved WCXXC catalytic motif and QSTL/M motif are boxed. The characteristic elements of the thioredoxin fold (α1, α2, α3, α4, α5, β1, β2, β3, and β4) are underlined.