title: Identification of biochemical and putative biological role of a xenolog from Escherichia coli using structural analysis.
abstract: YagE is a 33 kDa prophage protein encoded by CP4-6 prophage element in Escherichia coli K12 genome. Here, we report the structures of YagE complexes with pyruvate (PDB Id 3N2X) and KDGal (2-keto-3-deoxy galactonate) (PDB Id 3NEV) at 2.2A resolution. Pyruvate depletion assay in presence of glyceraldehyde shows that YagE catalyses the aldol condensation of pyruvate and glyceraldehyde. Our results indicate that the biochemical function of YagE is that of a 2-keto-3-deoxy gluconate (KDG) aldolase. Interestingly, E. coli K12 genome lacks an intrinsic KDG aldolase. Moreover, the over-expression of YagE increases cell viability in the presence of certain bactericidal antibiotics, indicating a putative biological role of YagE as a prophage encoded virulence factor enabling the survival of bacteria in the presence of certain antibiotics. The analysis implies a possible mechanism of antibiotic resistance conferred by the over-expression of prophage encoded YagE to E. coli.
authors.affiliation: Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai 625021, India.
authors.forename: Varun
authors.initials: V
authors.lastname: Bhaskar
authors.forename: Manoj
authors.initials: M
authors.lastname: Kumar
authors.forename: Sankar
authors.initials: S
authors.lastname: Manicka
authors.forename: Sunil
authors.initials: S
authors.lastname: Tripathi
authors.forename: Aparna
authors.initials: A
authors.lastname: Venkatraman
authors.forename: S
authors.initials: S
authors.lastname: Krishnaswamy
mesh_terms: D000446:Aldehyde-Lyases / Q000737:chemistry* / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D020134:Catalytic Domain; D049109:Cell Proliferation / Q000187:drug effects; D015169:Colony Count, Microbial; D019295:Computational Biology; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D007652:Oxo-Acid-Lyases; D039002:Prophages / Q000201:enzymology* / Q000502:physiology; D011485:Protein Binding; D019289:Pyruvic Acid / Q000737:chemistry / Q000378:metabolism; D013400:Sugar Acids / Q000737:chemistry / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D013400:Sugar Acids; C014726:2-oxo-3-deoxygalactonic acid; D019289:Pyruvic Acid; C093801:2-keto-3-deoxy-D-galactonate aldolase; D000446:Aldehyde-Lyases; D007652:Oxo-Acid-Lyases; C018728:N-acetylneuraminate lyase