Serine-195 and Histidine 57 need to stop fighting over protons.

Yay for dramatic enzymes. XD

Incidentally, I found out today that actually, there IS a monosaccharide with nine carbon atoms, which, by the naming standards of saccharides, would make it a nonose.

The material in question is neuraminic acid, often found as a residue in sialic acids. As it turns out, they serve as substrates for Neuraminidase enzymes, like the ones carried by influenza viruses - their H#/N# numbers are referring to isoforms of Hemaglutinin and Neuraminidase.

And that is why when you get the flu and sneeze your brains out you often wish you had nonose!