|Gene:||lhpC||Accession Number: G-16026 (MetaCyc)|
Synonyms: PP_1257, 1-pyrroline-4-hydroxy-2-carboxylate deaminase
Species: Pseudomonas putida KT2442
Subunit composition of
Δ1-pyrroline-4-hydroxy-2-carboxylate deaminase = [LhpC]8
Δ1-pyrroline-4-hydroxy-2-carboxylate deaminase subunit = LhpC
This enzyme catalyzes the third step in the bacterial 4-hydroxy-L-proline degradation pathway (see trans-4-hydroxy-L-proline degradation II). It is a unique member of the dihydropicolinate synthase/N-acetylneuraminate lyase family. Its encoding gene is contained within the 4-hydroxy-L-proline degradation operon of this organism [Watanabe12].
Disruption of the gene encoding this enzyme lead to loss of growth on both L-hydroxyproline and D-hydroxyproline, but not L-proline and D-proline, suggesting the specificity of this pathway for 4-hydroxy-L-proline degradation [Watanabe12].
Recombinant His6-tagged enzyme was overexpressed in Escherichia coli and purified. The native apparent molecular mass was approximately 275 kDa by gel filtration chromatography. The subunit apparent molecular mass was 35 kDa by SDS-PAGE, which suggested a homooctamer [Watanabe12].
|Map Position: [1,436,114 <- 1,437,061]|
Molecular Weight of Polypeptide: 34.075 kD (from nucleotide sequence), 35.0 kD (experimental) [Watanabe12 ]
Molecular Weight of Multimer: 275.0 kD (experimental) [Watanabe12]
Enzymatic reaction of: Δ1-pyrroline-4-hydroxy-2-carboxylate deaminase
Synonyms: 1-pyrroline-4-hydroxy-2-carboxylate deaminase
EC Number: 18.104.22.168
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
The reaction is favored in the direction shown.
In Pathways: trans-4-hydroxy-L-proline degradation II
This enzyme was assayed spectrophotometrically in a coupled assay using α-ketoglutaric semialdehyde dehydrogenase and monitoring the increase in absorbance of the NADPH produced [Watanabe12].
In earlier work the enzyme was found to be inducible when the the organism was grown on hydroxyproline as sole carbon and nitrogen source. The enzyme was shown to be highly substrate-specific. A reverse reaction could not be detected. The reaction product was characterized as 2,5-dioxovalerate [Singh65a].
T(opt): 37 °C [Singh65]
pH(opt): 6.5-7.5 [Singh65]
Singh65: Singh RM, Adams E (1965). "Enzymatic deamination of delta-1-pyrroline-4-hydroxy-2-carboxylate to 2,5-dioxovalerate (alpha-ketoglutaric semialdehyde)." J Biol Chem 240(11);4344-51. PMID: 5845838
Watanabe12: Watanabe S, Morimoto D, Fukumori F, Shinomiya H, Nishiwaki H, Kawano-Kawada M, Sasai Y, Tozawa Y, Watanabe Y (2012). "Identification and characterization of D-hydroxyproline dehydrogenase and Delta1-pyrroline-4-hydroxy-2-carboxylate deaminase involved in novel L-hydroxyproline metabolism of bacteria: metabolic convergent evolution." J Biol Chem 287(39);32674-88. PMID: 22833679
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