title: Loss of Homogentisate 1,2-Dioxygenase Activity in Bacillus anthracis Results in Accumulation of Protective Pigment.
abstract: Melanin production is important to the pathogenicity and survival of some bacterial pathogens. In Bacillus anthracis, loss of hmgA, encoding homogentisate 1,2-dioxygenase, results in accumulation of a melanin-like pigment called pyomelanin. Pyomelanin is produced in the mutant as a byproduct of disrupted catabolism of L-tyrosine and L-phenylalanine. Accumulation of pyomelanin protects B. anthracis cells from UV damage but not from oxidative damage. Neither loss of hmgA nor accumulation of pyomelanin alter virulence gene expression, sporulation or germination. This is the first investigation of homogentisate 1,2-dioxygenase activity in the Gram-positive bacteria, and these results provide insight into a conserved aspect of bacterial physiology.
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA, United States of America.
authors.forename: Hesong
authors.initials: H
authors.lastname: Han
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA, United States of America.
authors.forename: Liudmyla
authors.initials: L
authors.lastname: Iakovenko
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA, United States of America.
authors.forename: Adam C
authors.initials: AC
authors.lastname: Wilson
mesh_terms: D000881:Anthrax / Q000382:microbiology; D001408:Bacillus anthracis / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D001426:Bacterial Proteins / Q000378:metabolism; D004251:DNA Transposable Elements; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D050560:Homogentisate 1,2-Dioxygenase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008543:Melanins / Q000235:genetics / Q000378:metabolism*; D016296:Mutagenesis; D018384:Oxidative Stress; D010649:Phenylalanine / Q000378:metabolism; D020011:Protective Agents / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D008543:Melanins; D020011:Protective Agents; C023793:pyomelanin; D014443:Tyrosine; D010649:Phenylalanine; D050560:Homogentisate 1,2-Dioxygenase