Description: Homo sapiens kynureninase (KYNU), transcript variant 1, mRNA. (from RefSeq NM_003937) RefSeq Summary (NM_003937): 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. [provided by RefSeq, Nov 2010]. Gencode Transcript: ENST00000264170.9 Gencode Gene: ENSG00000115919.15 Transcript (Including UTRs) Position: hg38 chr2:142,877,664-143,055,833 Size: 178,170 Total Exon Count: 14 Strand: + Coding Region Position: hg38 chr2:142,885,368-143,042,172 Size: 156,805 Coding Exon Count: 13
ID:KYNU_HUMAN DESCRIPTION: RecName: Full=Kynureninase; EC=188.8.131.52; AltName: Full=L-kynurenine hydrolase; FUNCTION: 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. CATALYTIC ACTIVITY: L-kynurenine + H(2)O = anthranilate + L- alanine. CATALYTIC ACTIVITY: L-3-hydroxykynurenine + H(2)O = 3- hydroxyanthranilate + L-alanine. COFACTOR: Pyridoxal phosphate. ENZYME REGULATION: Inhibited by o-methoxybenzoylalanine (OMBA). BIOPHYSICOCHEMICAL PROPERTIES: Kinetic parameters: KM=493 uM for L-kynurenine (at pH 7.0); KM=28.3 uM for DL-3-hydroxykynurenine (at pH 7.0); KM=3.0 uM for DL-3-hydroxykynurenine (at pH 7.9); pH dependence: Optimum pH is 8.25 with DL-3-hydroxykynurenine as substrate; PATHWAY: Amino-acid degradation; L-kynurenine degradation; L- alanine and anthranilate from L-kynurenine: step 1/1. PATHWAY: Cofactor biosynthesis; NAD(+) biosynthesis; quinolinate from L-kynurenine: step 2/3. SUBUNIT: 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. INDUCTION: Increased levels in several cerebral and systemic inflammatory conditions. MASS SPECTROMETRY: Mass=52400; Method=MALDI; Range=1-465; Note=The reported mass is given to only three significant figures; Source=PubMed:11985583; 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 (PubMed:17334708). 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. SIMILARITY: Belongs to the kynureninase family. CAUTION: It has been reported that this enzyme possesses no measurable activity against L-kynurenine and is subject to inhibition by both L-kynurenine and D-kynurenine at pH 7.9 (PubMed:11985583).
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
ModBase Predicted Comparative 3D Structure on Q16719
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.