Genome Property Definition Page

NameKDO(2)-lipid A (Re LPS) biosynthesis and delivery
DescriptionLipid A is a component of the outer leaflet of the outer membrane of most gram-negative bacteria. It is one of three regions of bacterial lipopolysaccharide (LPS), along with the oligosaccharide core and the repeating O-antigen. In some strains, O-antigen may be missing and the lipid A-containing material may be designated lipooligosaccharide (LOS). Lipid A consists of a disaccharide (often beta-D-GlcN-(1-->6)-D-GlcN) with four attached acyl groups. Lipid A is attached to a 3-deoxy-D-manno-oct-2-ulosonic acid (KDO), a sugar moeity that becomes part of the LPS oligosaccharide inner core. Two of acyl groups of lipid A are then modified by further acylations into branched structures; acylation varies somewhat by species, and sometimes according to conditions within a species. The inner core typically contains at least two KDO and two heptose residues. The outer core and O-antigen regions are far more variable, and their biosynthesis is modeled in this property. LPS biosynthesis mutational studies have shown that, in a number of species, lipid A with two KDO residues but no additional residues of the inner core is the minimum required form of LPS for viability, called Re LPS or Re endotoxin. This genome property describes a set of well-conserved enzymes for biosynthesis of KDO(2)-lipid A that resembles but is not necessarily identical to the Re endotoxin of E. coli (nor as active in endotoxin assays), as well as a transporter, or flippase, responsible in most Proteobacteria for positioning lipid A in the outer membrane.
JCVI RoleBiosynthesis and degradation of surface polysaccharides and lipopolysaccharides
Parent PropertyGenProp0297: lipopolysaccharide biosynthesis
Literature References
[ 1 ] Sperandeo P, Cescutti R, Villa R, Di Benedetto C, Candia D, Deho G, Polissi A   Characterization of lptA and lptB, two essential genes implicated in lipopolysaccharide transport to the outer membrane of Escherichia coli.   J Bacteriol. 2007 Jan;189(1):244-53.  PMID 17056748
Web ReferencesMetaCyc:lipid-A-precursor biosynthesis

Step NameStep NumRequiredEvidence (Method)Evidence Go Terms
Source of UDP-N-acetylglucosamineUDPAGNOGenProp0750 (GENPROP): UDP-N-acetylglucosamine biosynthesis from fructose-6-phosphate
lipid A exporter MsbAexportNOTIGR02203 (HMM): lipid A export permease/ATP-binding protein MsbA
KDO-8 phosphate synthetasekdsAYESTIGR01362 (HMM): 3-deoxy-8-phosphooctulonate synthase
KDO cytidylyltransferasekdsBNOTIGR00466 (HMM): 3-deoxy-D-manno-octulosonate cytidylyltransferase
KDO 8-P phosphatasekdsCYESTIGR01670 (HMM): 3-deoxy-D-manno-octulosonate 8-phosphate phosphatase, YrbI family
UDP-N-acetylglucosamine O-acyltransferaselpxAYESTIGR01852 (HMM): acyl-[acyl-carrier-protein]-UDP-N-acetylglucosamine O-acyltransferase
lipid-A-disaccharide synthaselpxBYESTIGR00215 (HMM): lipid-A-disaccharide synthase
UDP-3-0-acyl N-acetylglucosamine deacetylaselpxCYESTIGR00325 (HMM): UDP-3-O-[3-hydroxymyristoyl] N-acetylglucosamine deacetylase
UDP-3-O-[3-hydroxymyristoyl] glucosamine N-acyltransferaselpxDYESTIGR01853 (HMM): UDP-3-O-[3-hydroxymyristoyl] glucosamine N-acyltransferase LpxD
UDP-2,3-diacylglucosamine hydrolaselpxHYESTIGR01854 (HMM): UDP-2,3-diacylglucosamine diphosphatase
PF06230 (HMM): PF06230 family
tetraacyldisaccharide 4'-kinaselpxKYESTIGR00682 (HMM): tetraacyldisaccharide 4'-kinase
add lauroyl to lipid IV-AlpxLYESTIGR02207 (HMM): lipid A biosynthesis lauroyl (or palmitoleoyl) acyltransferase
PF03279 (HMM): lipid A biosynthesis (KDO)2-(lauroyl)-lipid IVA acyltransferase
acylate lauroyl-lipid IV-AmsbBNOTIGR02208 (HMM): lipid A biosynthesis (KDO)2-(lauroyl)-lipid IVA acyltransferase
temporary_lpxH candidatetmp_lpxHNO
transferasewaaAYESPF04413 (HMM): 3-deoxy-D-manno-octulosonic-acid transferase

Parent Properties
GenProp0297lipopolysaccharide biosynthesis

Sibling Properties
GenProp0203LPS inner core biosynthesis, ketodeoxyoctonate and heptose type
GenProp0925Leptospira core LPS elements
GenProp0929LPS outer core, E. coli type
GenProp0966E. coli O-antigen biosynthesis
GenProp0994Leptospira interrogans-specific LPS components
GenProp0995Leptospira interrogans LPS associated transketolase