Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
twitter

MetaCyc Enzyme: L-arginine:pyruvate transaminase

Gene: aruH Accession Number: G-10354 (MetaCyc)

Synonyms: PA4976

Species: Pseudomonas aeruginosa

Subunit composition of L-arginine:pyruvate transaminase = [AruH]2
         L-arginine:pyruvate transaminase subunit = AruH

Summary:
The aruH gene of Pseudomonas aeruginosa encodes an L-arginine:pyruvate transaminase that converts L-arginine to 2-ketoarginine, the key reaction in an alternative arginine degradation pathway found in this organism. The gene was cloned, and fused to a His-tag, and the protein was expressed in Escherichia coli, purified and characterized [Yang07f]. The enzyme is a homodimer of 79.3 kDa, and requires pyridoxal 5'-phosphate for activity.

The enzyme is most active with L-arginine, but can accept several other amino acids as substrate (see below). The high Km value of AruH for L-arginine (13.9 mM) may explane why this pathway is not the preferred arginine degradation pathway in Pseudomonas aeruginosa and why it is only active when the major pathway (see arginine degradation II (AST pathway)) is blocked [Yang07f].

Gene Citations: [Yang07a]

Molecular Weight of Polypeptide: 43.0 kD (experimental) [Yang07f ]

Molecular Weight of Multimer: 79.3 kD (experimental) [Yang07f]

Unification Links: Entrez-gene:880915

Gene-Reaction Schematic: ?

Credits:
Created 03-Dec-2007 by Caspi R , SRI International


Enzymatic reaction of: L-arginine:pyruvate transaminase

EC Number: 2.6.1.84

L-arginine + pyruvate <=> 2-ketoarginine + L-alanine

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

This reaction is reversible.

Alternative Substrates for L-arginine: L-lysine [Yang07f ] , L-methionine [Yang07f ] , L-leucine [Yang07f ] , L-ornithine [Yang07f ] , L-glutamine [Yang07f ]

In Pathways: arginine degradation IX (arginine:pyruvate transaminase pathway)

Summary:
The calculated Vmax and kcat were 54.6 μmol/min/mg protein and 38.6 s-1. The apparent Km and catalytic efficiency (kcat/Km) for pyruvate were 1.6 mM and 24.1 mM-1 s-1, respectively. The apparent Km and catalytic efficiency (kcat/Km) for L-arginine were 13.9 mM and 2.8 mM-1 s-1, respectively [Yang07f].

Cofactors or Prosthetic Groups: pyridoxal 5'-phosphate [Yang07f]

Kinetic Parameters:

Substrate
Km (μM)
Citations
L-arginine
13900.0
[Yang07f]
pyruvate
1600.0
[Yang07f]

T(opt): 42 °C [Yang07f]

pH(opt): 9 [Yang07f]


References

Yang07a: Yang Z, Lu CD (2007). "Functional genomics enables identification of genes of the arginine transaminase pathway in Pseudomonas aeruginosa." J Bacteriol 189(11);3945-53. PMID: 17416670

Yang07f: Yang Z, Lu CD (2007). "Characterization of an arginine:pyruvate transaminase in arginine catabolism of Pseudomonas aeruginosa PAO1." J Bacteriol 189(11);3954-9. PMID: 17416668


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Thu Dec 18, 2014, biocyc13.