6pi6

Publication Abstract from PubMed

Atrazine is an s-triazine-based herbicide that is used in many countries around the world in many millions of tons per year. A small number of organisms, such as Pseudomonas sp. strain ADP, have evolved to use this modified s-triazine as a food source, and the various genes required to metabolize atrazine can be found on a single plasmid. The atomic structures of seven of the eight proteins involved in the breakdown of atrazine by Pseudomonas sp. strain ADP have been determined by X-ray crystallography, but the structures of the proteins required by the cell to import atrazine for use as an energy source are still lacking. The structure of AtzT, a periplasmic binding protein that may be involved in the transport of a derivative of atrazine, 2-hydroxyatrazine, into the cell for mineralization, has now been determined. The structure was determined by SAD phasing using an ethylmercury phosphate derivative that diffracted X-rays to beyond 1.9 A resolution. `Native' (guanine-bound) and 2-hydroxyatrazine-bound structures were also determined to high resolution (1.67 and 1.65 A, respectively), showing that 2-hydroxyatrazine binds in a similar way to the purportedly native ligand. Structural similarities led to the belief that it may be possible to evolve AtzT from a purine-binding protein to a protein that can bind and detect atrazine in the environment.

The evolving story of AtzT, a periplasmic binding protein.,Dennis ML, Esquirol L, Nebl T, Newman J, Scott C, Peat TS Acta Crystallogr D Struct Biol. 2019 Nov 1;75(Pt 11):995-1002. doi:, 10.1107/S2059798319013883. Epub 2019 Oct 31. PMID:31692473^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.