4UHN

Characterization of a Novel Transaminase from Pseudomonas sp. Strain AAC

Summary for 4UHN

• Entry DOI: 10.2210/pdb4uhn/pdb
• Related: 4UHM 4UHO
• Descriptor: OMEGA AMINO ACID-PYRUVATE AMINOTRANSFERASE, MAGNESIUM ION, GLYCEROL, ... (7 entities in total)
• Functional Keywords: biocatalysis, aminotransferase, transferase
• Biological source: PSEUDOMONAS SP.
• Total number of polymer chains: 1
• Total formula weight: 50966.65

Authors

Wilding, M.,Peat, T.S.,Newman, J.,Scott, C. (deposition date: 2015-03-25, release date: 2016-04-13, Last modification date: 2024-01-10)

Primary citation

Wilding, M.,Peat, T.S.,Newman, J.,Scott, C.
A Beta-Alanine Catabolism Pathway Containing a Highly Promiscuous Omega-Transaminase in the 12-Aminododecanate-Degrading Pseudomonas Sp. Strain Aac.
Appl.Environ.Microbiol., 82:3846-, 2016

PubMed Abstract: We previously isolated the transaminase KES23458 from Pseudomonas sp. strain AAC as a promising biocatalyst for the production of 12-aminododecanoic acid, a constituent building block of nylon-12. Here, we report the subsequent characterization of this transaminase. It exhibits activity with a broad substrate range which includes α-, β-, and ω-amino acids, as well as α,ω-diamines and a number of other industrially relevant compounds. It is therefore a prospective candidate for the biosynthesis of a range of polyamide monomers. The crystal structure of KES23458 revealed that the protein forms a dimer containing a large active site pocket and unusual phosphorylated histidine residues. To infer the physiological role of the transaminase, we expressed, purified, and characterized a dehydrogenase from the same operon, KES23460. Unlike the transaminase, the dehydrogenase was shown to be quite selective, catalyzing the oxidation of malonic acid semialdehyde, formed from β-alanine transamination via KES23458. In keeping with previous reports, the dehydrogenase was shown to catalyze both a coenzyme A (CoA)-dependent reaction to form acetyl-CoA and a significantly slower CoA-independent reaction to form acetate. These findings support the original functional assignment of KES23458 as a β-alanine transaminase. However, a seemingly well-adapted active site and promiscuity toward unnatural compounds, such as 12-aminododecanoic acid, suggest that this enzyme could perform multiple functions for Pseudomonas sp. strain AAC.

PubMed: 27107110
DOI: 10.1128/AEM.00665-16

Experimental method

X-RAY DIFFRACTION (2.21 Å)