EC Number |
Substrates |
Organism |
Products |
Reversibility |
---|
2.5.1.97 | more |
N-acetyl-D-mannosamine can not replace 2,4-diacetamido-2,4,6-trideoxy-beta-L-altropyranose as a substrate indicating that the enzyme does not possess detectable sialic acid synthase activity |
Campylobacter jejuni |
? |
- |
? |
2.5.1.97 | phosphoenolpyruvate + 2,4-diacetamido-2,4,6-trideoxy-beta-L-altropyranose + H2O |
pseudaminic acid biosynthesis |
Helicobacter pylori |
phosphate + 5,7-bis(acetylamino)-3,5,7,9-tetradeoxy-L-glycero-alpha-L-manno-2-nonulopyranosonic acid |
- |
? |
2.5.1.97 | phosphoenolpyruvate + 2,4-diacetamido-2,4,6-trideoxy-beta-L-altropyranose + H2O |
pseudaminic acid biosynthesis |
Campylobacter jejuni |
phosphate + 5,7-bis(acetylamino)-3,5,7,9-tetradeoxy-L-glycero-alpha-L-manno-2-nonulopyranosonic acid |
- |
? |
2.5.1.97 | phosphoenolpyruvate + 2,4-diacetamido-2,4,6-trideoxy-beta-L-altropyranose + H2O |
combining the five enzymes of pseudaminic acid biosynthesis (PseB, PseC, PseH, PseG, PseI) in a one-pot reaction results in 100% conversion of UDP-N-acetylglucosamine to pseudaminic acid after 20 h |
Helicobacter pylori |
phosphate + 5,7-bis(acetylamino)-3,5,7,9-tetradeoxy-L-glycero-alpha-L-manno-2-nonulopyranosonic acid |
- |
? |
2.5.1.97 | phosphoenolpyruvate + 2,4-diacetamido-2,4,6-trideoxy-beta-L-altropyranose + H2O |
phosphoenolpyruvate attacks the si-face of the aldehyde of 2,4-diacetamido-2,4,6-trideoxy-beta-L-altropyranose to generate an (S)-configuration at C-4. The proposed catalytic mechanism of pseudaminic acid synthase is the attack of the C-3 of PEP to the aldehyde of the open chain form of 6-deoxy-AltdiNAc and an attack of water to the C-2 of phosphoenolpyruvate to form a tetrahedral intermediate. The tetrahedral intermediate then collapses to release inorganic phosphate and form the open chain form of pseudaminic acid that cyclizes to the pyranose form in solution |
Campylobacter jejuni |
phosphate + 5,7-bis(acetylamino)-3,5,7,9-tetradeoxy-L-glycero-alpha-L-manno-2-nonulopyranosonic acid |
- |
? |