3B46

Crystal Structure of Bna3p, a Putative Kynurenine Aminotransferase from Saccharomyces cerevisiae

Summary for 3B46

• Entry DOI: 10.2210/pdb3b46/pdb
• Descriptor: Aminotransferase BNA3 (2 entities in total)
• Functional Keywords: kynurenine aminotransferase, llp, plp, cytoplasm, mitochondrion, pyridoxal phosphate, transferase
• Biological source: Saccharomyces cerevisiae (baker's yeast)
• Cellular location: Cytoplasm: P47039
• Total number of polymer chains: 2
• Total formula weight: 101261.02

Authors

Wogulis, M. (deposition date: 2007-10-23, release date: 2008-02-19, Last modification date: 2023-11-15)

Primary citation

Wogulis, M.,Chew, E.R.,Donohoue, P.D.,Wilson, D.K.
Identification of Formyl Kynurenine Formamidase and Kynurenine Aminotransferase from Saccharomyces cerevisiae Using Crystallographic, Bioinformatic and Biochemical Evidence.
Biochemistry, 47:1608-1621, 2008

PubMed Abstract: The essential enzymatic cofactor NAD+ can be synthesized in many eukaryotes, including Saccharomyces cerevisiae and mammals, using tryptophan as a starting material. Metabolites along the pathway or on branches have important biological functions. For example, kynurenic acid can act as an NMDA antagonist, thereby functioning as a neuroprotectant in a wide range of pathological states. N-Formyl kynurenine formamidase (FKF) catalyzes the second step of the NAD+ biosynthetic pathway by hydrolyzing N-formyl kynurenine to produce kynurenine and formate. The S. cerevisiae FKF had been reported to be a pyridoxal phosphate-dependent enzyme encoded by BNA3. We used combined crystallographic, bioinformatic and biochemical methods to demonstrate that Bna3p is not an FKF but rather is most likely the yeast kynurenine aminotransferase, which converts kynurenine to kynurenic acid. Additionally, we identify YDR428C, a yeast ORF coding for an alpha/beta hydrolase with no previously assigned function, as the FKF. We predicted its function based on our interpretation of prior structural genomics results and on its sequence homology to known FKFs. Biochemical, bioinformatics, genetic and in vivo metabolite data derived from LC-MS demonstrate that YDR428C, which we have designated BNA7, is the yeast FKF.

PubMed: 18205391
DOI: 10.1021/bi701172v

Experimental method

X-RAY DIFFRACTION (2 Å)