ArnA is a bifunctional enzyme, ArnADH protein consists of the C-terminal 345 residues of ArnA, starting at Thr-316 converted to an initiating methionine
ArnA is a bi-functional enzyme, the oxidative decarboxylation of UDP-glucuronic acid is catalyzed by the 345-residue C-terminal domain of ArnA. The 304-residue N-terminal domain catalyzes the N-10-formyltetrahydrofolate-dependent formylation of the 4''-amine of UDP-L-4-amino-4-deoxy-L-arabinose, generating the sugar nucleotide, uridine 5'-diphospho-beta-(4-deoxy-4-formamido-L-arabinose). The two domains of ArnA are expressed independently as active proteins in Escherichia coli. Both are required for maintenance of polymyxin resistance and 4-amino-4-deoxy-L-arabinose modification of lipid A. only the formylated sugar nucleotide is converted in vitro to an undecaprenyl phosphate-linked form by the enzyme ArnC
ArnA is a key enzyme in the lipid A modification pathway, and its deletion abolishes both the Ara4N-lipid A modification and polymyxin resistance. ArnA is a bifunctional enzyme. It can catalyze the NAD+-dependent decarboxylation of UDP-glucuronic acid to UDP-4-keto-arabinose and the N-10-formyltetrahydrofolate dependent formylation of UDP-4-amino-4-deoxy-L-arabinose
modification of the lipid A moiety of lipopolysaccharide by the addition of the sugar 4-amino-4-deoxy-L-arabinose is a strategy adopted by pathogenic Gram-negative bacteria to evade cationic antimicrobial peptides produced by the innate immune system. The bifunctional enzyme ArnA is required for 4-amino-4-deoxy-L-arabinose biosynthesis and catalyzes the NAD+-dependent oxidative decarboxylation of UDP-glucuronic acid to generate a UDP-4'-keto-pentose sugar and also catalyzes transfer of a formyl group from N-10-formyltetrahydrofolate to the 4'-amine of UDP-4-amino-4-deoxy-L-arabinose
the modification of lipid A with 4-amino-4-deoxy-L-arabinose allows gram-negative bacteria to resist the antimicrobial activity of cationic antimicrobial peptides and antibiotics such as polymyxin. ArnA is the first enzyme specific to the lipid A-Ara4N pathway. It contains two functionally and physically separable domains: a dehydrogenase domain (ArnA_DH) catalyzing the NAD+-dependent oxidative decarboxylation of UDP-glucuronic acid, and a transformylase domain that formylates UDP-4-amino-4-deoxy-L-arabinose
ArnA is a bi-functional enzyme. The oxidative decarboxylation of UDP-glucuronic acid is catalyzed by the 345-residue C-terminal domain of ArnA. The 304-residue N-terminal domain catalyzes the N-10-formyltetrahydrofolate-dependent formylation of the 4''-amine of UDP-4-amino-4-deoxy-L-arabinose, generating the sugar nucleotide, uridine 5'-diphospho-beta-(4-deoxy-4-formamido-L-arabinose)
ArnA is a bifunctional enzyme. It can catalyze the NAD+-dependent decarboxylation of UDP-glucuronic acid to UDP-4-keto-arabinose and the N-10-formyltetrahydrofolate dependent formylation of UDP-4-amino-4-deoxy-L-arabinose. The NAD+-dependent decarboxylating activity is contained in the 360 amino acid C-terminal domain of ArnA. This domain is separable from the N-terminal fragment, and its activity is identical to that of the full-length enzyme. T432, Y463, K467, R619, and S433 are involved in the mechanism of NAD+-dependent oxidation of the 4''-OH of the UDP-glucuronic acid and decarboxylation of the UDP-4-keto-glucuronic acid intermediate
modification of the lipid A moiety of lipopolysaccharide by the addition of the sugar 4-amino-4-deoxy-L-arabinose is a strategy adopted by pathogenic Gram-negative bacteria to evade cationic antimicrobial peptides produced by the innate immune system. The bifunctional enzyme ArnA is required for 4-amino-4-deoxy-L-arabinose biosynthesis and catalyzes the NAD+-dependent oxidative decarboxylation of UDP-glucuronic acid to generate a UDP-4'-keto-pentose sugar and also catalyzes transfer of a formyl group from N-10-formyltetrahydrofolate to the 4'-amine of UDP-4-amino-4-deoxy-L-arabinose. Residues Ser433 and Glu434 of the decarboxylase domain are required for the oxidative decarboxylation of UDP-glucuronate. Decarboxylase domain catalyzes both hydride abstraction (oxidation) from the C-4' position and the subsequent decarboxylation
UGA decarboxylase produces NADH and UDP-alpha-D-4-dehyroxylose as products, it can rebind NADH and UDP-alpha-D-4-dehyroxylose to slowly make UDP-alpha-D-xylose
hUXS contains a bound NAD+ cofactor that it recycles by first oxidizing UDP-alpha-D-glucuronic acid, and then reducing the UDP-alpha-D-4-dehydroxylose to produce UDP-alpha-D-xylose
one activity is to decarboxylate UDP-glucuronic acid to UDP-beta-L-threo-pentopyranosyl-4-ulose in the presence of NAD+. The second activity converts UDP-beta-L-threo-pentopyranosyl-4-ulose and NADH to UDP-xylose and NAD+, albeit at a lower rate. Following decarboxylation, there is stereospecific protonation at the C5pro-R position
ArnA is a bi-functional enzyme, the oxidative decarboxylation of UDP-glucuronic acid is catalyzed by the 345-residue C-terminal domain of ArnA. The 304-residue N-terminal domain catalyzes the N-10-formyltetrahydrofolate-dependent formylation of the 4''-amine of UDP-L-4-amino-4-deoxy-L-arabinose, generating the sugar nucleotide, uridine 5'-diphospho-beta-(4-deoxy-4-formamido-L-arabinose). The two domains of ArnA are expressed independently as active proteins in Escherichia coli. Both are required for maintenance of polymyxin resistance and 4-amino-4-deoxy-L-arabinose modification of lipid A. only the formylated sugar nucleotide is converted in vitro to an undecaprenyl phosphate-linked form by the enzyme ArnC
ArnA is a key enzyme in the lipid A modification pathway, and its deletion abolishes both the Ara4N-lipid A modification and polymyxin resistance. ArnA is a bifunctional enzyme. It can catalyze the NAD+-dependent decarboxylation of UDP-glucuronic acid to UDP-4-keto-arabinose and the N-10-formyltetrahydrofolate dependent formylation of UDP-4-amino-4-deoxy-L-arabinose
modification of the lipid A moiety of lipopolysaccharide by the addition of the sugar 4-amino-4-deoxy-L-arabinose is a strategy adopted by pathogenic Gram-negative bacteria to evade cationic antimicrobial peptides produced by the innate immune system. The bifunctional enzyme ArnA is required for 4-amino-4-deoxy-L-arabinose biosynthesis and catalyzes the NAD+-dependent oxidative decarboxylation of UDP-glucuronic acid to generate a UDP-4'-keto-pentose sugar and also catalyzes transfer of a formyl group from N-10-formyltetrahydrofolate to the 4'-amine of UDP-4-amino-4-deoxy-L-arabinose
the modification of lipid A with 4-amino-4-deoxy-L-arabinose allows gram-negative bacteria to resist the antimicrobial activity of cationic antimicrobial peptides and antibiotics such as polymyxin. ArnA is the first enzyme specific to the lipid A-Ara4N pathway. It contains two functionally and physically separable domains: a dehydrogenase domain (ArnA_DH) catalyzing the NAD+-dependent oxidative decarboxylation of UDP-glucuronic acid, and a transformylase domain that formylates UDP-4-amino-4-deoxy-L-arabinose
UGA decarboxylase produces NADH and UDP-alpha-D-4-dehyroxylose as products, it can rebind NADH and UDP-alpha-D-4-dehyroxylose to slowly make UDP-alpha-D-xylose
one activity is to decarboxylate UDP-glucuronic acid to UDP-beta-L-threo-pentopyranosyl-4-ulose in the presence of NAD+. The second activity converts UDP-beta-L-threo-pentopyranosyl-4-ulose and NADH to UDP-xylose and NAD+, albeit at a lower rate. Following decarboxylation, there is stereospecific protonation at the C5pro-R position
exogenous NAD+ stimulates enzyme activity, because a small fraction of hUXS releases the NADH and UDP-alpha-D-4-dehydroxylose intermediates as products during turnover. The resulting apoenzyme can be rescued by exogenous NAD+, explaining the apparent stimulatory effect of added cofactor
the ancestral enzyme of UDP-xylose synthase and UDP-apiose/UDP-xylose synthase is diverged to two distinct enzymatic activities in early bacteria. This separation gave rise to the current UDP-xylose synthase in animal, fungus, and plant as well as to the plant Uaxs and bacterial ArnA and U4kpxs homologues
crystallization of native and Se-Met decarboxylase protein. Good quality crystals are obtained with a precipitant solution of 3.2 M NaCl, 0.1 M Bistris, pH 5.2, using a drop containing 0.004 ml of protein and 0.004 ml of precipitant equilibrated against a reservoir of 0.1 ml of precipitant. Space group as P4(1)3(2), with cell dimensions a = b = c = 149.4 A, beta = gamma = 90°
hanging drop vapor diffusion method, crystal structure of the full-length bifunctional ArnA with UDP-glucuronic acid and ATP bound to the dehydrogenase domain. Binding of UDP-glucuronic acid triggers a 17 A conformational change in ArnA_DH that opens the NAD+ binding site while trapping UDP-glucuronic acid
structure of apo-ArnA and comparison with its ATP- and UDP-glucuronic acid-bound counterparts. In the crystal structure, a binding pocket at the centre of each ArnA trimer in its apo state pocket is occupied by a dithiothreitol molecule. Formation of the pocket is linked to a cascade of structural rearrangements that emerge from the NAD+-binding site. A small effector molecule is postulated that binds to the central pocket and modulates the catalytic properties of ArnA
purified recombinant UXS85-420 lacking the N-terminal membrane-spanning domain, hanging drop vapor diffusion method, precipitant containing 1.3 M ammonium sulfate, 0.1 M magnesium formate, and 0.15% PEG at 26°C, X-ray diffraction structure determination and analysis at 2.0 A resolution, molecular replacement
modification of the lipid A moiety of lipopolysaccharide by the addition of the sugar 4-amino-4-deoxy-L-arabinose is a strategy adopted by pathogenic Gram-negative bacteria to evade cationic antimicrobial peptides produced by the innate immune system. L-Ara4N biosynthesis is therefore a potential anti-infective target
engineering of Escherichia coli to ynthesize the plant-specific flavonoid O-pentosides quercetin 3-O-xyloside and quercetin 3-O-arabinoside. For UDP-xylose biosynthesis, genes UXS (UDP-xylose synthase) from Arabidopsis thaliana and ugd (UDP-glucose dehydrogenase) from E.scherichia coli, are overexpressed. The gene encoding ArnA, which competes with UXS for UDP-glucuronic acid, is deleted. For UDP-arabinose biosynthesis, UXE (UDP-xylose epimerase) is overexpressed. UDP-dependent glycosyltransferases are engineered to ensure specificity for UDP-xylose and UDP-arabinose. The srains thus obtained synthesize approximately 160 mg/liter of quercetin 3-O-xyloside and quercetin 3-O-arabinoside
Crystal structure of Escherichia coli ArnA (PmrI) decarboxylase domain. A key enzyme for lipid A modification with 4-amino-4-deoxy-L-arabinose and polymyxin resistance
Oxidative decarboxylation of UDP-glucuronic acid in extracts of polymyxin-resistant Escherichia coli. Origin of lipid a species modified with 4-amino-4-deoxy-L-arabinose
A formyltransferase required for polymyxin resistance in Escherichia coli and the modification of lipid A with 4-Amino-4-deoxy-L-arabinose. Identification and function oF UDP-4-deoxy-4-formamido-L-arabinose
Structure and function of both domains of ArnA, a dual function decarboxylase and a formyltransferase, involved in 4-amino-4-deoxy-L-arabinose biosynthesis
Identification of a bifunctional UDP-4-keto-pentose/UDP-xylose synthase in the plant pathogenic bacterium Ralstonia solanacearum strain GMI1000, a distinct member of the 4,6-dehydratase and decarboxylase family