Structural characterization of a novel luciferase-like monooxygenase from bacteria Pseudomonas meliae

Abstract

Luciferase is well known oxidative enzyme that produce bioluminescence. Since the discovery of luciferase, it has been used in many applications as emission of light during bioluminescent nature serves as a visual indicator for observation. In this study, the aim is to model and characterise a novelty of the luciferase-like monooxygenase protein/amino acid found in Pseudomonas meliae for its similarity to well established luciferase enzymes. The novel protein sequence was modelled and compared with established structures using bioinformatics methods. The Pseudomonas meliae, a plant pathogen that causes wood rot on nectarine, peach and Platanus spp. possess a luciferase-like monooxygenase that if activated, creates an intriguing prospect of using the pathogen’s bioluminescent as a visual indicator of diseased plants. If the pathogen’s own protein can be activated when the plant has been infected, its bioluminescent bacterial gall can be used to identify affected plants. In this study, the suitability of the luciferase like monooxygenase from P. meliae that infects chinaberry plants has to be modelled first, and then studied by comparing it with existing known luciferase. The sequence of Pseudomonas meliae (A0A0P9UTV8) was characterized and modelled using 3B9O as a template, using bioinformatics tools. Similarities between uncharacterized luciferase from Pseudomonas meliae and template from Geobacillus thermodenitrificans were analysed. The active site remains identical but with the exception of two amino acids; P.meliae Tyr138 instead of His138 and Leu311 instead of His311. All the other data 9on various properties of luciferase-like monooxygenase protein and its comparison between template alkane monooxygenase and model luciferase-like monooxygenase primary structure characteristics, similarities of amino acids sequences, binding sites, and predicted active sites of almost similar models. Both structures have similar key characteristics such as, high amino acid residue, Aspartic acid, and Glutamic acid. The results suggest that the absence of bioluminescence in P.meliae could be due to the evolutionary mutation in position 138 and 311. The Pseudomonas genera has been shown to react with light such as Pseudomonas fluorescens that emit luminescence under UV light as well as the application of bioluminescent Pseudomonas aeruginosa to assess the antimicrobial efficacy of wound dressings by monitoring light emission. Therefore, the P.meliae will have a potential future application, should the residues 138 and 311 be mutated to restore luciferase light emitting ability in future research. Suitability for further improvement, activation, and repurposing the luciferase from Pseudomonas meliae as a disease marker would depend on the outcome of this study.