Enzymes
| UniProtKB help_outline | 2,041 proteins |
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- Name help_outline UDP-4-amino-4-deoxy-β-L-arabinose Identifier CHEBI:58708 Charge -1 Formula C14H22N3O15P2 InChIKeyhelp_outline GWBAKYBSWHQNMQ-IAZOVDBXSA-M SMILEShelp_outline [NH3+][C@H]1CO[C@H](OP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](O)[C@@H]2O)n2ccc(=O)[nH]c2=O)[C@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline (6R)-10-formyltetrahydrofolate Identifier CHEBI:195366 Charge -2 Formula C20H21N7O7 InChIKeyhelp_outline AUFGTPPARQZWDO-YPMHNXCESA-L SMILEShelp_outline [H]C(=O)N(C[C@H]1CNC2=C(N1)C(=O)NC(N)=N2)C1=CC=C(C=C1)C(=O)N[C@@H](CCC([O-])=O)C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 10 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline UDP-4-deoxy-4-formamido-β-L-arabinose Identifier CHEBI:58709 Charge -2 Formula C15H21N3O16P2 InChIKeyhelp_outline QGYFHZBDXXNYAX-RTXATJJPSA-L SMILEShelp_outline [H]C(=O)N[C@H]1CO[C@H](OP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](O)[C@@H]2O)n2ccc(=O)[nH]c2=O)[C@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline (6S)-5,6,7,8-tetrahydrofolate Identifier CHEBI:57453 (Beilstein: 10223255) help_outline Charge -2 Formula C19H21N7O6 InChIKeyhelp_outline MSTNYGQPCMXVAQ-RYUDHWBXSA-L SMILEShelp_outline Nc1nc2NC[C@H](CNc3ccc(cc3)C(=O)N[C@@H](CCC([O-])=O)C([O-])=O)Nc2c(=O)[nH]1 2D coordinates Mol file for the small molecule Search links Involved in 41 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,717 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:24706 | RHEA:24707 | RHEA:24708 | RHEA:24709 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Structure and function of both domains of ArnA, a dual function decarboxylase and a formyltransferase, involved in 4-amino-4-deoxy-L-arabinose biosynthesis.
Williams G.J., Breazeale S.D., Raetz C.R.H., Naismith J.H.
Modification of the lipid A moiety of lipopolysaccharide by the addition of the sugar 4-amino-4-deoxy-L-arabinose (L-Ara4N) 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 ... >> More
Modification of the lipid A moiety of lipopolysaccharide by the addition of the sugar 4-amino-4-deoxy-L-arabinose (L-Ara4N) 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, because inhibiting its synthesis would render certain pathogens more sensitive to the immune system. The bifunctional enzyme ArnA, which is required for L-Ara4N biosynthesis, 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-L-Ara4N. We now report the crystal structure of the N-terminal formyltransferase domain in a complex with uridine monophosphate and N-5-formyltetrahydrofolate. Using this structure, we identify the active site of formyltransfer in ArnA, including the key catalytic residues Asn(102), His(104), and Asp(140). Additionally, we have shown that residues Ser(433) and Glu(434) of the decarboxylase domain are required for the oxidative decarboxylation of UDP-GlcUA. An E434Q mutant is inactive, suggesting that chemical rather than steric properties of this residue are crucial in the decarboxylation reaction. Our data suggest that the decarboxylase domain catalyzes both hydride abstraction (oxidation) from the C-4' position and the subsequent decarboxylation. << Less
J. Biol. Chem. 280:23000-23008(2005) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.
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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.
Breazeale S.D., Ribeiro A.A., McClerren A.L., Raetz C.R.H.
Modification of the phosphate groups of lipid A with 4-amino-4-deoxy-L-arabinose (L-Ara4N) is required for resistance to polymyxin and cationic antimicrobial peptides in Escherichia coli and Salmonella typhimurium. We previously demonstrated that the enzyme ArnA catalyzes the NAD+-dependent oxidat ... >> More
Modification of the phosphate groups of lipid A with 4-amino-4-deoxy-L-arabinose (L-Ara4N) is required for resistance to polymyxin and cationic antimicrobial peptides in Escherichia coli and Salmonella typhimurium. We previously demonstrated that the enzyme ArnA catalyzes the NAD+-dependent oxidative decarboxylation of UDP-glucuronic acid to yield the UDP-4''-ketopentose, uridine 5'-diphospho-beta-(L-threo-pentapyranosyl-4''-ulose), which is converted by ArnB to UDP-beta-(L-Ara4N). E. coli ArnA is a bi-functional enzyme with a molecular mass of approximately 74 kDa. The oxidative decarboxylation of UDP-glucuronic acid is catalyzed by the 345-residue C-terminal domain of ArnA. The latter shows sequence similarity to enzymes that oxidize the C-4'' position of sugar nucleotides, like UDP-galactose epimerase, dTDP-glucose-4,6-dehydratase, and UDP-xylose synthase. We now show that the 304-residue N-terminal domain catalyzes the N-10-formyltetrahydrofolate-dependent formylation of the 4''-amine of UDP-L-Ara4N, generating the novel sugar nucleotide, uridine 5'-diphospho-beta-(4-deoxy-4-formamido-L-arabinose). The N-terminal domain is highly homologous to methionyl-tRNA(f)Met formyltransferase. The structure of the formylated sugar nucleotide generated in vitro by ArnA was validated by 1H and 13C NMR spectroscopy. The two domains of ArnA were expressed independently as active proteins in E. coli. Both were required for maintenance of polymyxin resistance and L-Ara4N modification of lipid A. We conclude that N-formylation of UDP-L-Ara4N is an obligatory step in the biosynthesis of L-Ara4N-modified lipid A in polymyxin-resistant mutants. We further demonstrate that only the formylated sugar nucleotide is converted in vitro to an undecaprenyl phosphate-linked form by the enzyme ArnC. Because the L-Ara4N unit attached to lipid A is not derivatized with a formyl group, we postulate the existence of a deformylase, acting later in the pathway. << Less
J. Biol. Chem. 280:14154-14167(2005) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.