Structural features of PhoX, one of the phosphate-binding proteins from Pho regulon of Xanthomonas citri

• Published in: PloS one Vol. 12; no. 5; p. e0178162
• Main Authors: Pegos, Vanessa R, Santos, Rodrigo M L, Medrano, Francisco J, Balan, Andrea
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 22.05.2017; Public Library of Science (PLoS)
• Subjects: Amino Acid Sequence; Bacteria; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Binding proteins; Binding sites; Biology and Life Sciences; Chemotaxis; Cloning; Conformation; Crystal structure; Crystallography, X-Ray; E coli; Escherichia coli; Firmicutes; Gene duplication; Gene Expression Regulation, Bacterial; Genes; Genetic aspects; Ligands; Mycobacterium tuberculosis; Phosphate; Phosphate-Binding Proteins - chemistry; Phosphate-Binding Proteins - genetics; Phosphate-Binding Proteins - metabolism; Phosphates; Phosphates - metabolism; Physical Sciences; Physiological aspects; Phytopathogenic bacteria; Protein Conformation; Proteins; Regulon - genetics; Research and Analysis Methods; Sequence Alignment; Spectrum analysis; Structure; Tuberculosis; Xanthomonas - genetics; Xanthomonas - growth & development; Xanthomonas - metabolism; Xanthomonas citri; Brazil
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0178162

In Escherichia coli, the ATP-Binding Cassette transporter for phosphate is encoded by the pstSCAB operon. PstS is the periplasmic component responsible for affinity and specificity of the system and has also been related to a regulatory role and chemotaxis during depletion of phosphate. Xanthomonas citri has two phosphate-binding proteins: PstS and PhoX, which are differentially expressed under phosphate limitation. In this work, we focused on PhoX characterization and comparison with PstS. The PhoX three-dimensional structure was solved in a closed conformation with a phosphate engulfed in the binding site pocket between two domains. Comparison between PhoX and PstS revealed that they originated from gene duplication, but despite their similarities they show significant differences in the region that interacts with the permeases.