EC Number |
Substrates |
Organism |
Products |
Reversibility |
---|
2.3.1.191 | (3R)-3-hydroxyarachidonoyl-[acyl-carrier protein] + UDP-3-O-((3R)-3-hydroxymyristoyl)-alpha-D-glucosamine |
the external layer of the Gram-negative bacterial outer membrane is primarily composed of a protective, selectively permeable lipopolysaccharide. The biosynthesis of lipopolysaccharide relies on UDP-3-O-acyl-glucosamine N-acyltransferase (LpxD), which transfers 3-hydroxy-arachidonic acid from acyl carrier protein to the 2' amine of UDP-3-O-myristoyl glucosamine. CtLpxD is expected to utilize R-3-hydroxyarachidonoyl-[acyl-carrier protein] and UDP-3-O-(myristoyl)-R-D-glucosamine, based on the predominant molecular species of Chlamydia trachomatis lipid A. This proposal is not validated by in vitro assays |
Chlamydia trachomatis |
UDP-2-N-((3R)-3-hydroxyarachidonoyl)-3-O-((3R)-3-hydroxymyristoyl)-alpha-D-glucosamine + holo-[acyl-carrier protein] |
- |
? |
2.3.1.191 | (3R)-3-hydroxymyristoyl-[acyl-carrier protein] + UDP-3-O-((3R)-3-hydroxymyristoyl)-alpha-D-glucosamine |
a comparison of the lipid A structures shows that in Escherichia coli and Neisseria meningitidis, LpxD can be expected to have the same specificity, both adding 3-hydroxymyristoyl chains |
Neisseria meningitidis |
UDP-2,3-bis((3R)-3-hydroxymyristoyl)-alpha-D-glucosamine + holo-[acyl-carrier protein] |
- |
? |
2.3.1.191 | (3R)-3-hydroxymyristoyl-[acyl-carrier protein] + UDP-3-O-((3R)-3-hydroxymyristoyl)-alpha-D-glucosamine |
since only (R)-3-hydroxymyristate is found at the 2,3,2, and 3 positions of Escherichia coli lipid A, it is reassuring that both Escherichia coli acyltransferases display extraordinary specificity for (R)-3-hydroxymyristoyl-[acyl-carrier protein] |
Escherichia coli |
UDP-2,3-bis((3R)-3-hydroxymyristoyl)-alpha-D-glucosamine + holo-[acyl-carrier protein] |
- |
? |
2.3.1.191 | (3R)-3-hydroxymyristoyl-[acyl-carrier protein] + UDP-3-O-((3R)-3-hydroxymyristoyl)-alpha-D-glucosamine |
myristoyl-[acyl-carrier protein] does not serve as an acyl donor for the overproduced UDP-3-O-((R)-3-hydroxymyristoyl)-GlcN N-acyltransferase |
Escherichia coli |
UDP-2,3-bis((3R)-3-hydroxymyristoyl)-alpha-D-glucosamine + holo-[acyl-carrier protein] |
- |
? |
2.3.1.191 | (3R)-3-hydroxymyristoyl-[acyl-carrier protein] + UDP-3-O-((3R)-3-hydroxymyristoyl)-alpha-D-glucosamine |
third step of lipid A biosynthesis |
Escherichia coli |
UDP-2,3-bis(3-hydroxymyristoyl)-alpha-D-glucosamine + holo-[acyl-carrier protein] |
- |
? |
2.3.1.191 | (3R)-3-hydroxymyristoyl-[acyl-carrier protein] + UDP-3-O-((3R)-3-hydroxymyristoyl)-alpha-D-glucosamine |
compulsory ordered mechanism in which (3R)-3-hydroxymyristoyl-[acyl-carrier protein] binds prior to UDP-3-O-((3R)-3-hydroxymyristoyl)-alpha-D-glucosamine. The product, UDP-2,3-diacylglucosamine, dissociates prior to acyl-carrier protein |
Escherichia coli |
UDP-2,3-bis(3-hydroxymyristoyl)-alpha-D-glucosamine + holo-[acyl-carrier protein] |
- |
? |
2.3.1.191 | (3R)-3-hydroxymyristoyl-[acyl-carrier protein] + UDP-3-O-[(3R)-3-hydroxymyristoyl]-alpha-D-glucosamine |
- |
Escherichia coli |
UDP-2,3-bis[O-(3R)-3-hydroxymyristoyl]-alpha-D-glucosamine + a holo-[acyl-carrier protein] |
- |
ir |
2.3.1.191 | (3R)-3-hydroxymyristoyl-[acyl-carrier protein] + UDP-3-O-[(3R)-3-hydroxymyristoyl]-alpha-D-glucosamine |
- |
Francisella tularensis subsp. novicida |
UDP-2,3-bis[O-(3R)-3-hydroxymyristoyl]-alpha-D-glucosamine + a holo-[acyl-carrier protein] |
- |
ir |
2.3.1.191 | (3R)-3-hydroxymyristoyl-[acyl-carrier protein] + UDP-3-O-[(3R)-3-hydroxymyristoyl]-alpha-D-glucosamine |
- |
Arabidopsis thaliana |
UDP-2,3-bis[O-(3R)-3-hydroxymyristoyl]-alpha-D-glucosamine + a holo-[acyl-carrier protein] |
- |
ir |
2.3.1.191 | (3R)-3-hydroxymyristoyl-[acyl-carrier protein] + UDP-3-O-[(3R)-3-hydroxymyristoyl]-alpha-D-glucosamine |
the LpxD1 enzyme adds a 3-OH C18 acyl group at 37 °C (host), whereas the LpxD2 enzyme adds a 3-OH C16 acyl group at 18 °C (environment) |
Francisella tularensis subsp. novicida |
UDP-2,3-bis[O-(3R)-3-hydroxymyristoyl]-alpha-D-glucosamine + a holo-[acyl-carrier protein] |
- |
ir |