Genome of Halomonas Strain GFAJ-1, a Blueprint for Fame or Business as Usual
Evidence for arsenate in macromolecules that normally contain phosphate, most notably nucleic acids” (18). This extraordinary claim made in a research article in the December 2010 issue of Science express placed Halomonas sp. strain GFAJ-1 front and center of a fairly extensive discussion, quickly making this organism significantly interesting to a broad audience. It is apparent that the central question of whether arsenate can replace phosphate in DNA is still unresolved, as the 12 authors of the original paper hold to their conclusion as a reasonable interpretation of their data (17), while the majority of experts on arsenic microbiology and nucleic acid structure interpret the published data to be inconclusive (1, 2, 4,–,6, 9, 12,–,14). In early December 2011, 1 year after the Science paper appeared, the genome of GFAJ-1 was released in GenBank; now it is presented in a Genome Announcement by Phung et al. in this issue of the Journal of Bacteriology (10), providing some insight into the metabolic potential of this beguiling microorganism. However, there is agreement that the genome does not directly answer whether arsenate can substitute for phosphate in biomolecules, specifically DNA. Nevertheless, it helps contextualize an artist's canvas. Finishing a painting can be an emotional affair as an artist sees for the first time his or her vision made concrete. Scientists, as artists, long for this ephemeral moment. Over a year ago now, with publication of the original paper by Wolfe-Simon et al. (18), a few thought and hoped such a moment had arrived. Could poisonous arsenic also be the backbone of life, replacing phosphorus? Alas, the backlash was fierce, as can be expected for both scientific milestones and blunders (1, 2, 9, 12, 13, 15).