IN SILICO ANALYSIS AND FUNCTIONAL CHARACTERIZATION OF FHUB, A COMPONENT OF ERWINIA MALLOTIVORA FERRIC HYDROXAMATE UPTAKE SYSTEM

Abstract

Iron is a critical element for bacterial growth as most pathogenic bacteria relies on their host for iron supply. However, iron sources are bounded to the host iron binding protein and specific iron acquisition mechanism is required to chelate and transport the iron to the bacteria. Ferric hydroxamate uptake system or fhu is one of the transport systems that import iron in the form of ferric hydroxamate/ ferrichrome from the extracellular environment into the bacterial cytosol. In this present study, a detailed in silico structural analysis was conducted on an important component of fhu transport member from Erwinia mallotivora named as fhuB. This provide us the structural properties of the protein which includes the domain and 3D model, phylogenetic analysis and the membrane topology. For functional analysis, a knockout mutant of fhuB gene strain was generated to evaluate the effect of silencing this gene during E. mallotivora infection in papaya. When compared to the wild E. mallotivora strain, fhuB mutant strain of E. mallotivora loss its virulence in causing dieback disease symptom in papaya. The result of this study has revealed the significant role of iron acquisition and metabolism during E. mallotivora pathogenesis. This highlights fhuB role and importance as the target gene; to inhibit iron uptake in E. mallotivora for future study and as a part of future consideration for dieback disease management strategy in papaya.