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Names | |
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Other names plantazolicin A, PZN | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
PubChem CID | |
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Properties | |
C63H69N17O13S2 | |
Molar mass | 1336.47 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Plantazolicin (PZN) is a natural antibiotic produced by the gram-positive soil bacterium Bacillus velezensis FZB42 [1] (previously Bacillus amyloliquefaciens FZB42). [2] PZN has specifically been identified as a selective bactericidal agent active against Bacillus anthracis , the causative agent of anthrax. This natural product is a ribosomally synthesized and post-translationally modified peptide (RiPP); it can be classified further as a thiazole/oxazole-modified microcin (TOMM) or a linear azole-containing peptide (LAP). [3]
The significance of PZN stems from its narrow-spectrum antibiotic activity. Most antibiotics in clinical use are broad-spectrum, acting against a wide variety of bacteria, and antibiotic resistance to these drugs is common. In contrast, PZN is antibacterial against only a small number of species, including Bacillus anthracis .[ citation needed ]
The genes for the biosynthesis of PZN were first reported in 2008. [4] The natural product was then isolated in 2011 from Bacillus amyloliquefaciens . [5] The structure of PZN was solved later that year by two independent research groups, primarily through high-resolution mass spectrometry and NMR spectroscopy. [6] [7] In 2013, various biomimetic chemical synthesis studies of PZN were reported, including a total synthesis. [8]
In bacteria, plantazolicin (PZN) is synthesized first as an unmodified peptide via translation at the ribosome. A series of enzymes then chemically alter the peptide to install its post-translational modifications, including several azole heterocycles and an N-terminal amine dimethylation.[ citation needed ]
Specifically, during the biosynthesis of PZN in B. velezensis, a ribosomally-synthesized precursor peptide undergoes extensive post-translational modification, including cyclodehydrations and dehydrogenations, catalyzed by a trimeric enzyme complex. This process converts cysteine and serine/threonine residues into thiazole and (methyl)oxazole heterocycles [7] (as seen to the right).
The exact mechanism of the association of the trimeric enzyme complex with the N-terminal leader peptide region is not yet understood; however, it is thought that the leader peptide is cleaved from the core peptide putatively by the peptidase contained in the biosynthetic gene cluster. [9] Following leader peptide removal, the newly formed N-terminus undergoes methylation to yield an Nα,Nα-dimethylarginine. This final modification results in mature PZN.[ citation needed ]
Other organisms such as Bacillus pumilus , Clavibacter michiganensis subsp. sepedonicus , Corynebacterium urealyticum , and Brevibacterium linens have been identified with similar gene clusters that have the potential to produce PZN-like molecules. [7]