Identification of flavonoids as regulators of YbeY activity in Liberibacter asiaticus. (10th November 2019)

• Record Type: Journal Article
• Authors: Zuo, Ran; de Oliveira, Aline; Bullita, Enrica; Torino, Maria Ines; Padgett‐Pagliai, Kaylie A.; Gardner, Christopher L.; Harrison, Natalie A.; da Silva, Danilo; Merli, Marcelo L.; Gonzalez, Claudio F.; Lorca, Graciela L.
• Is Part Of: Environmental microbiology. Volume 21:Number 12(2019)
• Page Start: 4822
• Page End: 4835
• Publication Date: 2019-11-10
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; 579.17
• DOI: 10.1111/1462-2920.14831
• Languages: English
• ISSNs: 1462-2912

Abstract

Summary: Liberibacter asiaticus is the prevalent causative pathogen of Huanglongbing or citrus greening disease, which has resulted in a devastating crisis in the citrus industry. A thorough understanding of this pathogen's physiology and mechanisms to control cell survival is critical in the identification of therapeutic targets. YbeY is a highly conserved bacterial RNase that has been implicated in multiple roles. In this study, we evaluated the biochemical characteristics of the L . asiaticus YbeY (CLIBASIA_01560) and assessed its potential as a target for antimicrobials. YbeY Las was characterized as an endoribonuclease with activity on 3′ and 5′ termini of 16S and 23S rRNAs, and the capacity to suppress the E . coli ΔybeY phenotype. We predicted the YbeY Las protein:ligand interface and subsequently identified a flavone compound, luteolin, as a selective inhibitor. Site‐directed mutagenesis was subsequently used to identify key residues involved in the catalytic activity of YbeY Las . Further evaluation of naturally occurring flavonoids in citrus trees indicated that both flavones and flavonols had potent inhibitory effects on YbeY Las . Luteolin was subsequently examined for efficacy against L . asiaticus in Huanglongbing‐infected citrus trees, where a significant reduction in L . asiaticus gene expression was observed.