The final, open access version of Lygie's most recent paper is now available on-line.
The work described in this paper is the latest in a series on pieces in which we investigate the enzymes involved in degrading the herbicide atrazine. Like many herbicides and other pesticides, the use of atrazine contributes to high yields in broad acre cropping; however, atrazine has a somewhat mixed reputation, and so it's important to know about its fate in the environment.
The common soil bacterium Pseudomonas has evolved a catabolic pathway that lets it 'eat' atrazine - using it as a nitrogen source. This work contributes to our understanding of how Pseudomonas has evolved this pathway, and more broadly how bacteria repurpose existing enzymes for new metabolic functions. In this case, we were able to deduce the likely ancestor of AtzE (1-carboxybiuret amidohydrolase) from the presence of a small, unexpected ancillary protein (AtzG) that appears to be a the remaining vestige of a larger complex (the transamidosome - essential for making certain charged tRNAs).
Finding AtzG also alerted us to the presence of another small, previously unidentified protein in the atrazine catabolism pathway, AtzH, which we're currently investigating.
As well as the paper you can find an author profile from Lygie, an editorial piece from Tamara L. Hendrickson and a press release by Sasha Mushegian from the ASBMB.