Amino acid alignment of GDP-4-keto-6-deoxy-D-mannose-3,5-epimerase-4-reductases. The predicted amino acid sequence of schistosome GMER (Sm) is compared to GMERs of humans (Hs), Mus musculus (Mm), Drosophila melanogaster (Dm), Caenorhabditis elegans (Ce), Mortierella alpina (Ma), Arabidopsis thaliana (At-1, At-2) and Bacteroides fragilis (Bf) (accession numbers in Table 1). Alignment position is indicated above each block, and sequence length is reported to the right of each line. Positions of identity are indicated in black, and gray-highlighted positions are greater than 80% conserved among the sampled sequences. A well-conserved glycine-rich phosphate-binding loop (GxxGxxG), which mediates the binding of dinucleotide cofactors (e.g., NAD+/NADP+) by redox-associated enzymes , is underlined. Additionally, the catalytically important [S/T]-Y-K triad of the short-chain dehydrogenase/reductase-type enzymes is indicated by asterisks (*), and residues thought to be involved in proton exchange between GMER and its epimerization reaction intermediates are marked with carets (^) . Vector NTI Advance 11.0 software alignment settings: BLOSUM45 matrix, gap opening penalty = 12, gap extension penalty = 0.1, gap separation penalty range = 0, no residue-specific or hydrophobic residue gaps.