Sphaerocyclamide, a prenylated cyanobactin from the cyanobacterium Sphaerospermopsis sp. LEGE 00249

• Published in: Scientific reports Vol. 8; no. 1; pp. 14537 - 9
• Main Authors: Martins, Joana, Leikoski, Niina, Wahlsten, Matti, Azevedo, Joana, Antunes, Jorge, Jokela, Jouni, Sivonen, Kaarina, Vasconcelos, Vitor, Fewer, David P., Leão, Pedro N.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 28.09.2018; Nature Publishing Group
• Subjects: 140/131; 38/23; 38/44; 45/77; 631/92/349; 631/92/60; Antimicrobial activity; E coli; Humanities and Social Sciences; Mass spectrometry; Mass spectroscopy; multidisciplinary; NMR; Nuclear magnetic resonance; Peptides; Post-translation; Science; Science (multidisciplinary); Tyrosine; Biosynthetic Gene Cluster; Ribosomally Synthesized And Post-translationally Modified Peptides (RiPPs); Cyanobactins; Mass Spectrometry-based Screening; Marine Fouling Bacteria
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-32618-5

Cyanobactins are a family of linear and cyclic peptides produced through the post-translational modification of short precursor peptides. A mass spectrometry-based screening of potential cyanobactin producers led to the discovery of a new prenylated member of this family of compounds, sphaerocyclamide (1), from Sphaerospermopsis sp. LEGE 00249. The sphaerocyclamide biosynthetic gene cluster ( sph ) encoding the novel macrocyclic prenylated cyanobactin, was sequenced. Heterologous expression of the sph gene cluster in Escherichia coli confirmed the connection between genomic and mass spectrometric data. Unambiguous establishment of the orientation and site of prenylation required the full structural elucidation of 1 using Nuclear Magnetic Resonance (NMR), which demonstrated that a forward prenylation occurred on the tyrosine residue. Compound 1 was tested in pharmacologically or ecologically relevant biological assays and revealed moderate antimicrobial activity towards the fouling bacterium Halomonas aquamarina CECT 5000.