Crystal structure of the omega transaminase from Pseudomonas jessenii in the apo form, crystallized from succinateCrystal structure of the omega transaminase from Pseudomonas jessenii in the apo form, crystallized from succinate

Structural highlights

6g4b is a 2 chain structure with sequence from Achromobacter georgiopolitanum. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:,
Gene:CMK94_18730 (Achromobacter georgiopolitanum)
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Publication Abstract from PubMed

The biodegradation of the nylon-6 precursor caprolactam by a strain of Pseudomonas jessenii proceeds via ATP-dependent hydrolytic ring-opening to 6-aminohexanoate. This non-natural omega-amino acid is converted to 6-oxohexanoic acid by an aminotransferase (PjAT) belonging to the fold type I PLP enzymes. To understand the structural basis of 6-aminohexanoatate conversion, we solved different crystal structures and determined the substrate scope with a range of aliphatic and aromatic amines. Comparison with the homologous aminotransferases from Chromobacterium violaceum (CvAT) and Vibrio fluvialis (VfAT) showed that the PjAT enzyme has the lowest KM values (highest affinity) and highest specificity constant (kcat /KM ) with the caprolactam degradation intermediates 6-aminohexanoate and 6-oxohexanoic acid, in accordance with its proposed in vivo function. Five distinct three-dimensional structures of PjAT were solved by protein crystallography. The structure of the aldimine intermediate formed from 6-aminohexanoate and the PLP cofactor revealed the presence of a narrow hydrophobic substrate-binding tunnel leading to the cofactor and covered by a flexible arginine, which explains the high activity and selectivity of the PjAT with 6-aminohexanoate. The results suggest that the degradation pathway for caprolactam has recruited an aminotransferase that is well adapted to 6-aminohexanoate degradation. This article is protected by copyright. All rights reserved.

Biochemical properties of a Pseudomonas aminotransferase involved in caprolactam metabolism.,Palacio CM, Rozeboom HJ, Lanfranchi E, Meng Q, Otzen M, Janssen DB FEBS J. 2019 Jun 4. doi: 10.1111/febs.14950. PMID:31162815[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

  1. Palacio CM, Rozeboom HJ, Lanfranchi E, Meng Q, Otzen M, Janssen DB. Biochemical properties of a Pseudomonas aminotransferase involved in caprolactam metabolism. FEBS J. 2019 Jun 4. doi: 10.1111/febs.14950. PMID:31162815 doi:http://dx.doi.org/10.1111/febs.14950

6g4b, resolution 1.80Å

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