Bioorganic Chemistry and Bio-Crystallography Laboratory (B(2)Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy. Electronic address:
Published: June 2018
AI Article Synopsis
Article Abstract
The Gram-negative bacterium Erwinia amylovora is the etiological agent of fire blight, a devastating disease which affects Rosaceae such as apple, pear and quince. The siderophore desferrioxamine E plays an important role in bacterial pathogenesis by scavenging iron from the host. DfoJ, DfoA and DfoC are the enzymes responsible for desferrioxamine production starting from lysine. We have determined the crystal structures of each enzyme in the desferrioxamine E pathway and demonstrate that the biosynthesis involves the concerted action of DfoJ, followed by DfoA and lastly DfoC. These data provide the first crystal structures of a Group II pyridoxal-dependent lysine decarboxylase, a cadaverine monooxygenase and a desferrioxamine synthetase. DfoJ is a homodimer made up of three domains. Each monomer contributes to the completion of the active site, which is positioned at the dimer interface. DfoA is the first structure of a cadaverine monooxygenase. It forms homotetramers whose subunits are built by two domains: one for FAD and one for NADP binding, the latter of which is formed by two subdomains. We propose a model for substrate binding and the role of residues 43-47 as gate keepers for FAD binding and the role of Arg97 in cofactors turnover. DfoC is the first structure of a desferrioxamine synthetase and the first of a multi-enzyme siderophore synthetase coupling an acyltransferase domain with a Non-Ribosomal Peptide Synthetase (NRPS)-Independent Siderophore domain (NIS).
Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea.
Background: Fire blight, caused by Erwinia amylovora, poses a significant threat to global agriculture, with antibiotic-resistant strains necessitating alternative solutions such as phage therapy. Scaling phage therapy to an industrial level requires efficient mass-production methods, particularly in optimizing the seed culture process. In this study, we investigated large-scale E.
The bacterial pathogen causes fire blight on rosaceous plants, including apples and their wild relatives. The pathogen uses the type III secretion pathogenicity island to inject effector proteins, such as Eop1, into host plants, leading to disease phenotypes in susceptible genotypes. In contrast, resistant genotypes exhibit quantitative resistance associated with genomic regions and/or R-gene-mediated qualitative resistance to withstand the pathogen.
Phytocytokines belong to a category of small secreted peptides with signaling functions that play pivotal roles in diverse plant physiological processes. However, due to low levels of sequence conservation across plant species and poorly understood biological functions, the accurate detection and annotation of corresponding genes is challenging. The availability of a high-quality apple (Malus domestica) genome has enabled the exploration of five phytocytokine gene families, selected on the basis of their altered expression profiles in response to biotic stresses.
The study focused on identifying microorganisms that can antagonize the bacteria causing fire blight, testing 127 unknown bacterial isolates.
Two strains, BCA3 and BCA19, were found to be effective, with BCA19 showing 13.9% stronger antagonistic activity.
Further tests revealed that BCA19's culture filtrates inhibited the motility of the target bacteria and contained antibacterial compounds like indole, which effectively inhibited bacterial growth, suggesting BCA19 could serve as a biological control agent.
Fire blight caused by Erwinia amylovora is one of the destructive diseases in the family of Rosaceae plants, including apple and pear, in the world. Since the first report in 2015, the number of infected farms and area steadily increased in Korea. In case of eradication failure against this disease, protection strategies using both chemicals and biocontrol agents should be established.
