Mannitol dehydrogenases signature

The following dehydrogenases have been shown [1] to be evolutionary related:

• Mannitol-1-phosphate 5-dehydrogenase (EC 1.1.1.17) (gene mtlD), which catalyzes the NAD-dependent reduction of mannitol 1-phosphate into fructose 6-phosphate.
• Mannitol 2-dehydrogenase (EC 1.1.1.67) (gene mtlK), which catalyzes the NAD-dependent reduction of mannitol into fructose.
• Mannonate oxidoreductase (EC 1.1.1.57) (fructuronate reductase) (gene uxuB), which catalyzes the NAD-dependent reduction of fructuronate into mannonate.
• Escherichia coli hypothetical protein ydfI.
• Escherichia coli hypothetical protein yeiQ.
• Yeast hypothetical protein YEL070w.

As a signature pattern, we selected a conserved region located in the central section of these enzymes.