kynureninase (KYNU)

Kynureninase (KYNU), also known as L-kynurenine hydrolase), is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. Kynureninase is one of the enzymes involved in the biosynthesis of NAD cofactors from tryptophan through the kynurenine pathway. kynureninase is in subgroup IVa of the aminotransferases, along with nifS, CsdB, and serine-pyruvate aminotransferase, which suggests that kynureninase has an aminotransferase fold.

kynureninase (KYNU) Related Areas

Neuroscience>>Synaptic Protein>>Kynureninase

kynureninase (KYNU) Alternative Names

Kynureninase, KYNU, OTTHUMP00000162647, OTTHUMP00000204304, OTTHUMP00000204305  [Homo sapiens]

Kynureninase, Kynu, RP23-303O15.1, 4432411A05Rik [Mus musculus]

Summaries for kynureninase (KYNU)

Entrez Gene summary for kynureninase (KYNU):

Kynureninase is a pyridoxal-5'-phosphate (pyridoxal-P) dependent enzyme that catalyzes the cleavage of L-kynurenine and L-3-hydroxykynurenine into anthranilic and 3-hydroxyanthranilic acids, respectively. Kynureninase is involved in the biosynthesis of NAD cofactors from tryptophan through the kynurenine pathway. Alternative splicing results in multiple transcript variants.

OMIM - description for kynureninase (KYNU):

Kynureninase (EC 3.7.1.33) is a 3-hydroxykynureninase-type enzyme involved in the kynurenine pathway for the biosynthesis of NAD cofactors from tryptophan. It catalyzes the conversion of L-3-hydroxykynurenine and L-kynurenine to 3-hydroxyanthranilic acid and anthranilic acid, respectively. The reaction is pyridoxal-5-prime-dependent and is sensitive to nutritional vitamin B6 deprivation in mammals. Studies in mouse, rat, and pig suggest that kynureninase is a 95-kD kD homodimer predominantly located in the cytoplasm

Wikipedia summary for kynureninase (KYNU):

Kynureninase or L-Kynurenine hydrolase (KYNU) (EC 3.7.1.3) is a PLP dependent enzyme that catalyses the cleavage of kynurenine (Kyn) into anthranilic acid (Ant). It can also act on 3hKyn (to produce 3hAnt) and some other (3-arylcarbonyl)-alanines. Humans express one kynureninase enzyme that is encoded by the KYNU gene located on chromosome 2.[2][3] KYNU is part of the pathway for the catabolism of Trp and the biosynthesis of NAD cofactors from tryptophan (Trp). Kynureninase catalyzes the following reaction:

Human kynureninase (KYNU) Protein General Information

 

• Protein names: Recommended name: Kynureninase
• Sequence length: 465 AA.
• Sequence similarities: Belongs to the kynureninase family.
• Pathway: Amino-acid degradation; L-kynurenine degradation; L-alanine and anthranilate from L-kynurenine: step 1/1. Cofactor biosynthesis; NAD(+) biosynthesis; quinolinate from L-kynurenine: step 2/3.
• Subunit structure: Homodimer.
• Subcellular location: Cytoplasm
• Tissue specificity: Expressed in all tissues tested (heart, brain placenta, lung, liver, skeletal muscle, kidney and pancreas). Highest levels found in placenta, liver and lung. Expressed in all brain regions.
• Involvement in disease: Note=Xanthurenic aciduria manifesting as massive urinary excretion of large amounts of kynurenine, 3-hydroxykynurenine and xanthurenic acid has been observed in an individual carrying a homozygous missense change in KYNU (Ref.10). The urinary pattern in the patient suggests kynureninase deficiency and a block in the conversion of kynurenine and 3-hydroxykynurenine to anthranilate and 3-hydroxyanthranilate, respectively.

General information above from UniProt

Function for kynureninase (KYNU) Protein

UniProtKB:

Catalyzes the cleavage of L-kynurenine (L-Kyn) and L-3-hydroxykynurenine (L-3OHKyn) into anthranilic acid (AA) and 3-hydroxyanthranilic acid (3-OHAA), respectively. Has a preference for the L-3-hydroxy form. Also has cysteine-conjugate-beta-lyase activity.

Genatlas:

• pyridoxal-5'-phosphate (pyridoxal-P) dependent enzyme involved in the biosynthesis of NAD cofactors from tryptophan through the kynurenine pathway

Homology for human kynureninase (KYNU)

• homolog to rattus Kynu