The biosynthesis of pyoverdines
Authors:Michael T. Ringel1 and Thomas Brüser1
doi: 10.15698/mic2018.10.649
Volume 5, pp. 424 to 437, published 28/08/2018.
1 Institute of Microbiology, Leibniz University Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany.
Keywords:
Pyoverdines, iron starvation, siderophores, Pseudomonas fluorescens, Pseudomonas aeruginosa, non-ribosomal peptide synthetases, periplasmic tailoring
Corresponding Author(s):
Conflict of interest statement:
The authors declare no conflict of interest.
Please cite this article as:
Michael T. Ringel and Thomas Brüser (2018). The biosynthesis of pyoverdines. Microbial Cell 5(10): 424-437. doi: 10.15698/mic2018.10.649
© 2018 Ringel and Brüser. This is an open-access article released under the terms of the Creative Commons Attribution (CC BY) license, which allows the unrestricted use, distribution, and reproduction in any medium, provided the original author and source are acknowledged.
Abstract:
Pyoverdines are fluorescent siderophores of pseudomonads that play important roles for growth under iron-limiting conditions. The production of pyoverdines by fluorescent pseudomonads permits their colonization of hosts ranging from humans to plants. Prominent examples include pathogenic or non-pathogenic species such as Pseudomonas aeruginosa, P. putida, P. syringae, or P. fluorescens. Many distinct pyoverdines have been identified, all of which have a dihydroxyquinoline fluorophore in common, derived from oxidative cyclizations of non-ribosomal peptides. These serve as precursor of pyoverdines and are commonly known as ferribactins. Ferribactins of distinct species or even strains often differ in their sequence, resulting in a large variety of pyoverdines. However, synthesis of all ferribactins begins with an L-Glu/D-Tyr/L-Dab sequence, and the fluorophore is generated from the D-Tyr/L-Dab residues. In addition, the initial L-Glu residue is modified to various acids and amides that are responsible for the range of distinguishable pyoverdines in individual strains. While ferribactin synthesis is a cytoplasmic process, the maturation to the fluorescent pyoverdine as well as the tailoring of the initial glutamate are exclusively periplasmic processes that have been a mystery until recently. Here we review the current knowledge of pyoverdine biosynthesis with a focus on the recent advancements regarding the periplasmic maturation and tailoring reactions.