Structural Insights on Two Hypothetical Secretion Chaperones from Xanthomonas axonopodis pv. citri

Abstract

Several Gram-negative bacterial pathogens have developed type III secretion systems (T3SSs) to deliver virulence proteins directly into eukaryotic cells in a process essential for many diseases. The type III secretion processes require customized chaperones with high specificity for binding partners, thus providing the secretion to occur. Due to the very low sequence similarities among secretion chaperones, annotation and discrimination of a great majority of them is extremely difficult and a task with low scores even if genes are encountered that codify for small (<20 kDa) proteins with low pI and a tendency to dimerise. Concerning about this, herein, we present structural features on two hypothetical T3SSs chaperones belonging to plant pathogen Xanthomonas axonopodis pv. citri and suggest how low resolution models based on Small Angle X-ray Scattering patterns can provide new structural insights that could be very helpful in their analysis and posterior classification.

Elucidating Protein Involvement in the Stabilization of the Biogenic Silver Nanoparticles

“…The UV-Vis spectrum displays two main bands, an SPR band at 440 nm, characteristic of the AgNP presence, and an additional band at 280 nm, which could be attributed to the aromatic amino acids of the capping proteins [ 69 ]. It is well-known that the absorption band in this region arises due to the electronic excitations in tryptophan, tyrosine and/or phenylalanine residues in fungal proteins [ 69 – 71 ]. These results confirm the AgNPs formation and the presence of fungal proteins.…”

Orange waste as a biomass for 2G-ethanol production using low cost enzymes and co-culture fermentation

“…citri (Xac) proteins, a virulent Gram-negative pathogen that causes citrus canker disease. [11][12][13] These bacteria enter into the host-plant through the stomata, and through an impressive arsenal of proteins, including pectinases and celullases, cause visible circular spot-wounds. 14 Several bacteria and fungi have been reported to produce cocktails of hydrolytic depolymerising lignocellulosic enzymes and usually fungi are considered a better option in terms of enzyme varieties and yields.…”

A Secreted Chorismate Mutase from Xanthomonas arboricola pv. juglandis Attenuates Virulence and Walnut Blight Symptoms

“…This protein also was characterized as one of the most abundant proteins in outer membrane vesicles of X. citri [ 50 ] and it is secreted only by the hrpB4 mutant grown in XAM1 medium [ 41 ]. AKJ12_17400 is homologous to XAC0419, annotated as HPF/RaiA family ribosome-associated protein in X. arboricola , a stress-response protein that binds the ribosomal subunit interface and arrests translation by interfering with aminoacyl-tRNA binding to the ribosomal A site [ 51 ]. This ribosome-associated inhibitor protein stabilizes bacterial ribosomes under stress, stationary phase, and normal growth conditions and may be correlated with T3SS [ 51 ].…”

“…AKJ12_17400 is homologous to XAC0419, annotated as HPF/RaiA family ribosome-associated protein in X. arboricola , a stress-response protein that binds the ribosomal subunit interface and arrests translation by interfering with aminoacyl-tRNA binding to the ribosomal A site [ 51 ]. This ribosome-associated inhibitor protein stabilizes bacterial ribosomes under stress, stationary phase, and normal growth conditions and may be correlated with T3SS [ 51 ]. AKJ12_14465 is a secreted protein homologous to XAC3439, a protein regulated by diffusible signal factor (DSF)/rpf genes [ 52 ].…”