Predicted amino acid alignment of GalE proteins from various gram-negative bacteria. The consensus sequence is shown at the bottom. Both strains of M. catarrhalis have an additional 23 residues at the N-terminal end of the protein. Boldface, amino acids that are in the binding pocket of the folded protein and that have been shown to interact with the substrate (UDP-sugar) or the cofactor (NAD+). Residues that interact with NAD+ are in italics, and residues that interact with UDP-sugar are underlined (15, 33, 49, 50). M. cat. 25238, M. catarrhalis ATCC strain 25238 (GenBank accession no. AF248583); M. cat. 2951, M. catarrhalis strain 2951 (GenBank accession no. AF248584); N. men. B, N. meningitidis serotype B strain FAM20 (SwissProt accession no. Q59624); N. gon., N. gonorrhoeae (SwissProt accession no. Q05026); B. sub., B. subtilis (SwissProt accession no. P55180); H. inf., H. influenzae (SwissProt accession no. P24325). E. coli SwissProt accession no., P09147.