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Characterization of biosynthetic genes of ascamycin/dealanylascamycin featuring a 5'-O-sulfonamide moiety in Streptomyces sp. JCM9888.

Zhao C, Qi J, Tao W, He L, Xu W, Chan J, Deng Z - PLoS ONE (2014)

Bottom Line: JCM9888.Two flavin adenine dinucleotide (FAD)-dependent chlorinase genes acmX and acmY were characterized which are significantly remote from acmA-W and postulated to be required for adenine C2-halogenation.Notably gene disruption of acmE resulted in a mutant which could only produce dealanylascamycin but was blocked in its ability to biosynthesize ascamycin, revealing its key role of conversion of dealanylascamycin to ascamycin.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education) and School of Pharmaceutical Sciences, Wuhan University, 185 East Lake Road, Wuhan, 430071, PR China.

ABSTRACT
Ascamycin (ACM) and dealanylascamycin (DACM) are nucleoside antibiotics elaborated by Streptomyces sp. JCM9888. The later shows broad spectrum inhibition activity to various gram-positive and gram-negative bacteria, eukaryotic Trypanosoma and is also toxic to mice, while ascamycin is active against very limited microorganisms, such as Xanthomonas. Both compounds share an unusual 5'-O-sulfonamide moiety which is attached to an adenosine nucleoside. In this paper, we first report on the 30 kb gene cluster (23 genes, acmA to acmW) involved in the biosynthesis of these two antibiotics and a biosynthetic assembly line was proposed. Of them, six genes (AcmABGKIW) are hypothetical genes involved in 5'-O-sulfonamide formation. Two flavin adenine dinucleotide (FAD)-dependent chlorinase genes acmX and acmY were characterized which are significantly remote from acmA-W and postulated to be required for adenine C2-halogenation. Notably gene disruption of acmE resulted in a mutant which could only produce dealanylascamycin but was blocked in its ability to biosynthesize ascamycin, revealing its key role of conversion of dealanylascamycin to ascamycin.

No MeSH data available.


Related in: MedlinePlus

Gene organization of ascamycin/dealanylascamycin biosynthesis pathway.A) AcmA to AcmW. B) Chlorinases acmX and acmY.
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pone-0114722-g002: Gene organization of ascamycin/dealanylascamycin biosynthesis pathway.A) AcmA to AcmW. B) Chlorinases acmX and acmY.

Mentions: Streptomyces sp. JCM9888 is unusual in its ability to biosynthesize two nucleoside antibiotics: dealanylascamycin (1) and ascamycin (2) [20] (Fig. 1). As they are both featured with a 5′-O-sulfonamide moiety, we suspected sulfate metabolite related genes are required for the antibiotic production. Partial genome sequencing of Streptomyces genome revealed a 30,488 bp contiguous DNA sequence with an overall GC content of 66.7% (GenBank accession number KJ817374). Bioinformatics analysis of the sequence revealed 23 ORFs (acmA-W) and the deduced functions of individual ORFs are annotated and summarized in Table 1. Of them, 6 genes are proposed to be related to 5′-O-sulfonamide biosynthesis (acmA, acmB, acmG, acmI, acmK, acmW) (Fig. 2A). Notably, no halogenases were obvious around the gene cluster while BLASTp searches highlighted that two hypothetical flavin-dependent chlorinases (acmX and acmY) (GenBank accession number KJ817375) lying adjacent to each other on the chromosome in a distance of approx. 1 million basepair from acmA-W (Fig. 2B). AcmX and AcmY were shown to share high homology to all known FAD-dependent chlorinases, such as ChlB4 (accession number AAZ77674) from Streptomyces antibiotics which participate in chlorothricin biosynthesis (65% and 57% protein sequence identity respectively) [32]. Their analogy to proteins required for aromatic moiety chlorination suggested that they are potential candidates of the ascamycin/dealanylascamycin chlorinases as both two antibiotics possess a chlorine atom at C2-position of adenine.


Characterization of biosynthetic genes of ascamycin/dealanylascamycin featuring a 5'-O-sulfonamide moiety in Streptomyces sp. JCM9888.

Zhao C, Qi J, Tao W, He L, Xu W, Chan J, Deng Z - PLoS ONE (2014)

Gene organization of ascamycin/dealanylascamycin biosynthesis pathway.A) AcmA to AcmW. B) Chlorinases acmX and acmY.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4257720&req=5

pone-0114722-g002: Gene organization of ascamycin/dealanylascamycin biosynthesis pathway.A) AcmA to AcmW. B) Chlorinases acmX and acmY.
Mentions: Streptomyces sp. JCM9888 is unusual in its ability to biosynthesize two nucleoside antibiotics: dealanylascamycin (1) and ascamycin (2) [20] (Fig. 1). As they are both featured with a 5′-O-sulfonamide moiety, we suspected sulfate metabolite related genes are required for the antibiotic production. Partial genome sequencing of Streptomyces genome revealed a 30,488 bp contiguous DNA sequence with an overall GC content of 66.7% (GenBank accession number KJ817374). Bioinformatics analysis of the sequence revealed 23 ORFs (acmA-W) and the deduced functions of individual ORFs are annotated and summarized in Table 1. Of them, 6 genes are proposed to be related to 5′-O-sulfonamide biosynthesis (acmA, acmB, acmG, acmI, acmK, acmW) (Fig. 2A). Notably, no halogenases were obvious around the gene cluster while BLASTp searches highlighted that two hypothetical flavin-dependent chlorinases (acmX and acmY) (GenBank accession number KJ817375) lying adjacent to each other on the chromosome in a distance of approx. 1 million basepair from acmA-W (Fig. 2B). AcmX and AcmY were shown to share high homology to all known FAD-dependent chlorinases, such as ChlB4 (accession number AAZ77674) from Streptomyces antibiotics which participate in chlorothricin biosynthesis (65% and 57% protein sequence identity respectively) [32]. Their analogy to proteins required for aromatic moiety chlorination suggested that they are potential candidates of the ascamycin/dealanylascamycin chlorinases as both two antibiotics possess a chlorine atom at C2-position of adenine.

Bottom Line: JCM9888.Two flavin adenine dinucleotide (FAD)-dependent chlorinase genes acmX and acmY were characterized which are significantly remote from acmA-W and postulated to be required for adenine C2-halogenation.Notably gene disruption of acmE resulted in a mutant which could only produce dealanylascamycin but was blocked in its ability to biosynthesize ascamycin, revealing its key role of conversion of dealanylascamycin to ascamycin.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education) and School of Pharmaceutical Sciences, Wuhan University, 185 East Lake Road, Wuhan, 430071, PR China.

ABSTRACT
Ascamycin (ACM) and dealanylascamycin (DACM) are nucleoside antibiotics elaborated by Streptomyces sp. JCM9888. The later shows broad spectrum inhibition activity to various gram-positive and gram-negative bacteria, eukaryotic Trypanosoma and is also toxic to mice, while ascamycin is active against very limited microorganisms, such as Xanthomonas. Both compounds share an unusual 5'-O-sulfonamide moiety which is attached to an adenosine nucleoside. In this paper, we first report on the 30 kb gene cluster (23 genes, acmA to acmW) involved in the biosynthesis of these two antibiotics and a biosynthetic assembly line was proposed. Of them, six genes (AcmABGKIW) are hypothetical genes involved in 5'-O-sulfonamide formation. Two flavin adenine dinucleotide (FAD)-dependent chlorinase genes acmX and acmY were characterized which are significantly remote from acmA-W and postulated to be required for adenine C2-halogenation. Notably gene disruption of acmE resulted in a mutant which could only produce dealanylascamycin but was blocked in its ability to biosynthesize ascamycin, revealing its key role of conversion of dealanylascamycin to ascamycin.

No MeSH data available.


Related in: MedlinePlus