Literature summary for 2.6.1.87 extracted from

  • Breazeale, S.D.; Ribeiro, A.A.; Raetz, C.R.
    Origin of lipid A species modified with 4-amino-4-deoxy-L-arabinose in polymyxin-resistant mutants of Escherichia coli. An aminotransferase (ArnB) that generates UDP-4-deoxyl-L-arabinose (2003), J. Biol. Chem., 278, 24731-24739.
    View publication on PubMed

Cloned(Commentary)

Cloned (Comment) Organism
overexpressed using a T7lac promoter-driven construct, hexahistidine-tagged fusion protein Escherichia coli

Localization

Localization Comment Organism GeneOntology No. Textmining
cytoplasm
-
Escherichia coli
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-

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
UDP-beta-L-threo-pentapyranos-4-ulose + L-glutamate Escherichia coli ArnB catalyzes the reversible transfer of the amino group from glutamate to the acceptor, uridine 5'-(beta-L-threo-pentapyranosyl-4''-ulose diphosphate), the intermediate that is synthesized by ArnA from UDP-glucuronic acid.the enzyme is highly selective for glutamate as the amine donor, but the equilibrium constant in the direction of UDP-4-amino-4-deoxy-beta-L-arabinose formation is unfavorable UDP-4-amino-4-deoxy-beta-L-arabinose + 2-oxoglutarate
-
r

Organism

Organism UniProt Comment Textmining
Escherichia coli P77690
-
-

Purification (Commentary)

Purification (Comment) Organism
-
Escherichia coli

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
UDP-beta-L-threo-pentapyranos-4-ulose + L-glutamate ArnB catalyzes the reversible transfer of the amino group from glutamate to the acceptor, uridine 5'-(beta-L-threo-pentapyranosyl-4''-ulose diphosphate), the intermediate that is synthesized by ArnA from UDP-glucuronic acid.the enzyme is highly selective for glutamate as the amine donor, but the equilibrium constant in the direction of UDP-4-amino-4-deoxy-beta-L-arabinose formation is unfavorable Escherichia coli UDP-4-amino-4-deoxy-beta-L-arabinose + 2-oxoglutarate
-
r
UDP-beta-L-threo-pentapyranos-4-ulose + L-glutamate the enzyme is highly selective for glutamate as the amine donor, but the equilibrium constant in the direction of UDP-4-amino-4-deoxy-beta-L-arabinose formation is unfavorable. The rate of transamination with L-methionine, L-glutamine, and L-alanine is measurable at 5%, 2%, and 1%, respectively, of the rate observed with L-glutamate Escherichia coli UDP-4-amino-4-deoxy-beta-L-arabinose + 2-oxoglutarate
-
r

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
30
-
assay at Escherichia coli

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
7.5
-
assay at Escherichia coli

Cofactor

Cofactor Comment Organism Structure
pyridoxal 5'-phosphate the pyridoxal phosphate is converted to the pyridoxamine form in the presence of excess glutamate Escherichia coli