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Cyanobactins from Cyanobacteria: Current Genetic and Chemical State of Knowledge.

Martins J, Vasconcelos V - Mar Drugs (2015)

Bottom Line: Apart from non-ribosomal peptides and polyketides, ribosomally synthesized and post-translationally modified peptides (RiPPs) are one of the leading groups of bioactive compounds produced by cyanobacteria.It is assumed that the primary source of cyanobactins is cyanobacteria, although these compounds have also been isolated from marine animals such as ascidians, sponges and mollusks.The aim of this review is to update the current knowledge of cyanobactins, recognized as being produced by cyanobacteria, and to emphasize their genetic clusters and chemical structures as well as their bioactivities, ecological roles and biotechnological potential.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto 4169-007, Portugal. joana.o.martins@gmail.com.

ABSTRACT
Cyanobacteria are considered to be one of the most promising sources of new, natural products. Apart from non-ribosomal peptides and polyketides, ribosomally synthesized and post-translationally modified peptides (RiPPs) are one of the leading groups of bioactive compounds produced by cyanobacteria. Among these, cyanobactins have sparked attention due to their interesting bioactivities and for their potential to be prospective candidates in the development of drugs. It is assumed that the primary source of cyanobactins is cyanobacteria, although these compounds have also been isolated from marine animals such as ascidians, sponges and mollusks. The aim of this review is to update the current knowledge of cyanobactins, recognized as being produced by cyanobacteria, and to emphasize their genetic clusters and chemical structures as well as their bioactivities, ecological roles and biotechnological potential.

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General biosynthesis of cyanobactins that contain azoline heterocycles. Heterocyclization and proteolytic tailoring to produce macrocycles succeed translation of the core peptide. Multiple copies of the core peptide and recognition sequences may exist. Additional tailoring such as prenylation and oxidation/dehydrogenation to azoles may occur. Additional modifications are occasionally present. Adapted with permission from [2] (http://dx.doi.org/10.1039/c2np20085f). Copyright © The Royal Society of Chemistry, 2015.
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marinedrugs-13-06910-f002: General biosynthesis of cyanobactins that contain azoline heterocycles. Heterocyclization and proteolytic tailoring to produce macrocycles succeed translation of the core peptide. Multiple copies of the core peptide and recognition sequences may exist. Additional tailoring such as prenylation and oxidation/dehydrogenation to azoles may occur. Additional modifications are occasionally present. Adapted with permission from [2] (http://dx.doi.org/10.1039/c2np20085f). Copyright © The Royal Society of Chemistry, 2015.

Mentions: Cyanobactin genetic clusters (approximately from 8 to 19 kb in length) have only been identified in cyanobacteria [11]. The active cyanobactin gene clusters always encode: (1) two protease genes, A (N-terminal protease) and G (C-terminal protease), that are related to patA and patG genes from the patellamide biosynthetic pathway, also known as pat (both A and G genes comprehend a domain of unknown function (DUF) and a macrocyclase domain which is only present in the G-protease [33]);(2) a precursor peptide gene E, homolog to patE, which directly encodes the cyanobactin structure that acts as a substrate for post-translational modifications and, (3) two genes B and C, which are related to patB and patC, that encode short conserved proteins of an unidentified function [9,10]. Although B and C genes are conserved among nearly all cyanobactin genetic clusters, studies have demonstrated that these genes are non-essential [34]. In addition, the cyanobactin gene clusters may also encode homologs of PatD and/or PatF, denoted as D-protein (cyclodehydratase) and F-protein (prenyltransferase), as well as thiazoline/oxazoline dehydrogenases (responsible for the aromatization of the heterocycles to thiazoles and oxazoles), methyltransferases and other non-characterized proteins (Figure 2) [10]. The D gene is only present in cyanobactin biosynthetic pathways that produce compounds with heterocyclized amino acids (see Section 5). In contrast, the F gene seems to be present in all cyanobactin pathways, with the exception of the non-prenylated trichamide (see Section 5 and Section 6). Nevertheless, this gene was proven to be essential for the synthesis of the non-prenylated patellamides, suggesting that it may have a distinct function in this biosynthetic pathway [34].


Cyanobactins from Cyanobacteria: Current Genetic and Chemical State of Knowledge.

Martins J, Vasconcelos V - Mar Drugs (2015)

General biosynthesis of cyanobactins that contain azoline heterocycles. Heterocyclization and proteolytic tailoring to produce macrocycles succeed translation of the core peptide. Multiple copies of the core peptide and recognition sequences may exist. Additional tailoring such as prenylation and oxidation/dehydrogenation to azoles may occur. Additional modifications are occasionally present. Adapted with permission from [2] (http://dx.doi.org/10.1039/c2np20085f). Copyright © The Royal Society of Chemistry, 2015.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663559&req=5

marinedrugs-13-06910-f002: General biosynthesis of cyanobactins that contain azoline heterocycles. Heterocyclization and proteolytic tailoring to produce macrocycles succeed translation of the core peptide. Multiple copies of the core peptide and recognition sequences may exist. Additional tailoring such as prenylation and oxidation/dehydrogenation to azoles may occur. Additional modifications are occasionally present. Adapted with permission from [2] (http://dx.doi.org/10.1039/c2np20085f). Copyright © The Royal Society of Chemistry, 2015.
Mentions: Cyanobactin genetic clusters (approximately from 8 to 19 kb in length) have only been identified in cyanobacteria [11]. The active cyanobactin gene clusters always encode: (1) two protease genes, A (N-terminal protease) and G (C-terminal protease), that are related to patA and patG genes from the patellamide biosynthetic pathway, also known as pat (both A and G genes comprehend a domain of unknown function (DUF) and a macrocyclase domain which is only present in the G-protease [33]);(2) a precursor peptide gene E, homolog to patE, which directly encodes the cyanobactin structure that acts as a substrate for post-translational modifications and, (3) two genes B and C, which are related to patB and patC, that encode short conserved proteins of an unidentified function [9,10]. Although B and C genes are conserved among nearly all cyanobactin genetic clusters, studies have demonstrated that these genes are non-essential [34]. In addition, the cyanobactin gene clusters may also encode homologs of PatD and/or PatF, denoted as D-protein (cyclodehydratase) and F-protein (prenyltransferase), as well as thiazoline/oxazoline dehydrogenases (responsible for the aromatization of the heterocycles to thiazoles and oxazoles), methyltransferases and other non-characterized proteins (Figure 2) [10]. The D gene is only present in cyanobactin biosynthetic pathways that produce compounds with heterocyclized amino acids (see Section 5). In contrast, the F gene seems to be present in all cyanobactin pathways, with the exception of the non-prenylated trichamide (see Section 5 and Section 6). Nevertheless, this gene was proven to be essential for the synthesis of the non-prenylated patellamides, suggesting that it may have a distinct function in this biosynthetic pathway [34].

Bottom Line: Apart from non-ribosomal peptides and polyketides, ribosomally synthesized and post-translationally modified peptides (RiPPs) are one of the leading groups of bioactive compounds produced by cyanobacteria.It is assumed that the primary source of cyanobactins is cyanobacteria, although these compounds have also been isolated from marine animals such as ascidians, sponges and mollusks.The aim of this review is to update the current knowledge of cyanobactins, recognized as being produced by cyanobacteria, and to emphasize their genetic clusters and chemical structures as well as their bioactivities, ecological roles and biotechnological potential.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto 4169-007, Portugal. joana.o.martins@gmail.com.

ABSTRACT
Cyanobacteria are considered to be one of the most promising sources of new, natural products. Apart from non-ribosomal peptides and polyketides, ribosomally synthesized and post-translationally modified peptides (RiPPs) are one of the leading groups of bioactive compounds produced by cyanobacteria. Among these, cyanobactins have sparked attention due to their interesting bioactivities and for their potential to be prospective candidates in the development of drugs. It is assumed that the primary source of cyanobactins is cyanobacteria, although these compounds have also been isolated from marine animals such as ascidians, sponges and mollusks. The aim of this review is to update the current knowledge of cyanobactins, recognized as being produced by cyanobacteria, and to emphasize their genetic clusters and chemical structures as well as their bioactivities, ecological roles and biotechnological potential.

Show MeSH