EC Number   |
Natural Substrates |
|---|
  2.7.1.181 | ATP + alpha-D-Man-(1->2)-alpha-D-Man-(1->2)-alpha-D-Man-(1->3)-alpha-D-Man-(1->3)-[alpha-D-Man-(1->2)-alpha-D-Man-(1->2)-alpha-D-Man-(1->3)-alpha-D-Man-(1->3)]n-alpha-D-Man-(1->3)-alpha-D-Man-(1->3)-alpha-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol |
the chain length of bacterial lipopolysaccharide O antigens is determined in the ATP-binding cassette (ABC) transporter-dependent pathway. Escherichia coli O8 polymannan is synthesized in the cytoplasm, and an ABC transporter exports the nascent polymer across the inner membrane prior to completion of the lipopolysaccharide molecule. The polymannan O antigens has nonreducing terminal methyl groups. The 3-O-methyl group in serotype O8 is transferred from S-adenosylmethionine by the WbdDO8 enzyme, and this modification terminates polymerization. Methyl groups are added to the O9a polymannan in a reaction dependent on preceding phosphorylation. The bifunctional WbdDO9a catalyzes both reactions |
| 2.7.1.181 | ATP + alpha-D-Man-(1->2)-alpha-D-Man-(1->2)-alpha-D-Man-(1->3)-alpha-D-Man-(1->3)-[alpha-D-Man-(1->2)-alpha-D-Man-(1->2)-alpha-D-Man-(1->3)-alpha-D-Man-(1->3)]n-alpha-D-Man-(1->3)-alpha-D-Man-(1->3)-alpha-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol |
the phosphorylation of the O9a O-polysaccharide is a prerequisite for methylation. Terminal phosphorylation of the O9a repeating unit prevents polymer elongation by the mannosyltransferases and thus phosphorylation alone is sufficient for chain-length control of the O9a O-polysaccharide |
| 2.7.1.181 | ATP + alpha-D-Man-(1->2)-alpha-D-Man-(1->2)-[alpha-D-Man-(1->3)-alpha-D-Man-(1->3)-alpha-D-Man-(1->2)-alpha-D-Man-(1->2)]n-alpha-D-Man-(1->3)-alpha-D-Man-(1->3)-alpha-D-Man-(1->3)-alpha-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol |
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