6bmc

Publication Abstract from PubMed

In Pseudomonas aeruginosa , the shikimate pathway end product, chorismate, serves as the last common precursor for the biosynthesis of both primary aromatic metabolites, including phenylalanine, tyrosine, and tryptophan, and secondary aromatic metabolites, including phenazine-1-carboxylic acid and pyocyanin. The enzyme 3-deoxy-D- arabino -heptulosonate 7-phosphate synthase (DAH7PS) catalyses the first committed step of the shikimate pathway, en route to chorismate. P. aeruginosa expresses multiple, distinct, DAH7PSs that are associated with either primary or secondary aromatic compound biosynthesis. Here we report the structure of a type II DAH7PS, encoded by phzC as part of the duplicated phenazine biosynthetic cluster, from P. aeruginosa (PAO1) revealing for the first time the structure of a type II DAH7PS involved in secondary metabolism. The omission of the structural elements a2aand a2b, relative to other characterised type II DAH7PSs, leads to the formation of an alternative, dimeric, solution-state structure for the type II DAH7PSs with oligomeric interfaces that have not previously been characterised and that do not facilitate the formation of aromatic amino acid allosteric binding sites. The sequence similarity, and in particular the common N-terminal extension, suggests a common origin for the type II DAH7PSs from P. aeruginosa. The results described in this study support the further classification of the type II DAH7PSs as type IIAand type IIBbased on sequence characteristics, structure and function of the resultant proteins, and defined physiological roles within primary or secondary metabolism.

Structural and functional characterisation of the entry point to pyocyanin biosynthesis in Pseudomonas aeruginosa defines a new 3-deoxy-D- arabino -heptulosonate 7-phosphate synthase subclass.,Sterritt OW, Lang EJM, Kessans SA, Ryan TM, Demeler B, Jameson GB, Parker EJ Biosci Rep. 2018 Sep 21. pii: BSR20181605. doi: 10.1042/BSR20181605. PMID:30242059^[1]

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