3LT5

X-ray Crystallographic structure of a Pseudomonas Aeruginosa Azoreductase in complex with balsalazide

Summary for 3LT5

• Entry DOI: 10.2210/pdb3lt5/pdb
• Related: 2V9C 3KEG
• Descriptor: FMN-dependent NADH-azoreductase 1, FLAVIN MONONUCLEOTIDE, GLYCEROL, ... (5 entities in total)
• Functional Keywords: azoreductase, balsalazide, hydrazo, inflammatory bowel disease, p. aeruginosa, flavoprotein, fmn, oxidoreductase
• Biological source: Pseudomonas aeruginosa
• Total number of polymer chains: 2
• Total formula weight: 48057.75

Authors

Ryan, A.,Laurieri, N.,Westwood, I.,Wang, C.-J.,Lowe, E.,Sim, E. (deposition date: 2010-02-15, release date: 2010-05-12, Last modification date: 2023-11-01)

Primary citation

Ryan, A.,Laurieri, N.,Westwood, I.,Wang, C.-J.,Lowe, E.,Sim, E.
A Novel Mechanism for Azoreduction
J.Mol.Biol., 400:24-37, 2010

PubMed Abstract: Azoreductases are important due to their ability to activate anti-inflammatory azo pro-drugs and to detoxify azo dyes. Three genes encoding azoreductases have been identified in Pseudomonas aeruginosa. We describe here a comparison of the three enzymes. The pure recombinant proteins each have a distinct substrate specificity profile against a range of azo substrates. Using the structure of P. aeruginosa azoreductase (paAzoR) 1 and the homology models of paAzoR2 and paAzoR3, we have identified residues important for substrate specificity. We have defined a novel flavin mononucleotide binding cradle, which is a recurrent motif in many flavodoxin-like proteins. A novel structure of paAzoR1 with the azo pro-drug balsalazide bound within the active site was determined by X-ray crystallography and demonstrates that the substrate is present in a hydrazone tautomer conformation. We propose that the structure with balsalazide bound represents an enzyme intermediate and, together with the flavin mononucleotide binding cradle, we propose a novel catalytic mechanism.

PubMed: 20417637
DOI: 10.1016/j.jmb.2010.04.023

Experimental method

X-RAY DIFFRACTION (2.3 Å)