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Paenimacrolidin, a novel macrolide antibiotic from Paenibacillus sp. F6-B70 active against methicillin-resistant Staphylococcus aureus.

Wu XC, Qian CD, Fang HH, Wen YP, Zhou JY, Zhan ZJ, Ding R, Li O, Gao H - Microb Biotechnol (2010)

Bottom Line: Elucidation of the structure by nuclear magnetic resonance and infrared spectroscopy revealed that the active compound, paenimacrolidin (PAM), was a novel 22-membered macrolide with side-chains.The antibiotic capacity of PAM was compromised by its instability, which can be overcome significantly with addition of an anti-oxidant.To our knowledge, this is the first report of the isolation of an active macrolide from paenibacilli, which may be a promising source of novel antibiotics.

View Article: PubMed Central - PubMed

Affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China. mblab@163.com

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Related in: MedlinePlus

Sequence analyses of KS domains of Paenibacillus sp. F6‐B70. A. A complete module was deduced from a sequenced fragment between two KS domains. The Kirromycin gene cluster was used as the reference as it contains both cis‐ and trans‐AT PKSs (Weber et al., 2008). B. Neighbour‐joining cladogram of KS domains. Bars indicate 10% amino acid sequence divergence. KS numbering refers to the position within the gene cluster starting from the upstream end. The cis‐AT KS3 and KS5 from the erythromycin PKS was used as outgroup. Clade types were shown in roman numbers together with the main substrate type (detailed in Nguyen et al., 2008). The accession numbers of sequences from GenBank database are Bae KS2, ABS74061; Bae KS6, ABS74062; Bae KS12, ABS74064; Dif KS3, ABS74564; Dif KS9, ABS74561; Dif KS14, ABS74558; Ery KS3, AAV51821; Ery KS5, AAV51822; Mln KS3, ABS73797; Mmp KS6, AAM12913; Onn KS3, AAV97870; Ta KS8, ABF92489. Abbreviations: Bae, bacillaene; Dif, difficidin; Mmp, mupirocin; Mln, macrolactin; Onn, onnamide; Ta, myxovirescin.
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f2: Sequence analyses of KS domains of Paenibacillus sp. F6‐B70. A. A complete module was deduced from a sequenced fragment between two KS domains. The Kirromycin gene cluster was used as the reference as it contains both cis‐ and trans‐AT PKSs (Weber et al., 2008). B. Neighbour‐joining cladogram of KS domains. Bars indicate 10% amino acid sequence divergence. KS numbering refers to the position within the gene cluster starting from the upstream end. The cis‐AT KS3 and KS5 from the erythromycin PKS was used as outgroup. Clade types were shown in roman numbers together with the main substrate type (detailed in Nguyen et al., 2008). The accession numbers of sequences from GenBank database are Bae KS2, ABS74061; Bae KS6, ABS74062; Bae KS12, ABS74064; Dif KS3, ABS74564; Dif KS9, ABS74561; Dif KS14, ABS74558; Ery KS3, AAV51821; Ery KS5, AAV51822; Mln KS3, ABS73797; Mmp KS6, AAM12913; Onn KS3, AAV97870; Ta KS8, ABF92489. Abbreviations: Bae, bacillaene; Dif, difficidin; Mmp, mupirocin; Mln, macrolactin; Onn, onnamide; Ta, myxovirescin.

Mentions: For PKS, 22 independent clones were sequenced and only four different nucleotide sequences were obtained (Table 1). The deduced amino acid sequences of these four unique DNA fragments were highly related (72.6–77.7% identity) to known trans‐AT PKS sequences, suggesting that F6‐B70 hosts trans‐AT PKSs. To verify the structure of PKS in F6‐B70, the primers derived from two independent KS domains were used to amplify DNA fragments in between and a 4209 bp fragment was obtained. Sequence alignment with representative PKS clusters revealed that the fragment contains five domains, including two KS, one dehydratase (DH), one ketoreductase and one ACP (Fig. 2A) (Weber et al., 2008), confirming that strain F6‐B70 contains trans‐PKS. It has been reported that the ∼230‐amino‐acid internal region of KS domains generated by PCR was sufficient to provide structural information (Nguyen et al., 2008). We thus constructed a phylogenetic tree using a neighbour‐joining algorithm based on the unique PKS sequences of F6‐B70 and the closest homologues. As shown in Fig. 2B, all of these four KS sequences were clustered into trans‐AT PKSs clades, indicating that F6‐B70 hosts trans‐AT PKSs. Three KS sequences, PKSI‐3, PKSI‐4 and PKSI‐5, belong to clade I, implicating a branched substrate. On the contrary, PKSI‐2 was grouped into the single‐bond subclade of clade V, suggesting that the substrate may contain a single bond between two specific carbons.


Paenimacrolidin, a novel macrolide antibiotic from Paenibacillus sp. F6-B70 active against methicillin-resistant Staphylococcus aureus.

Wu XC, Qian CD, Fang HH, Wen YP, Zhou JY, Zhan ZJ, Ding R, Li O, Gao H - Microb Biotechnol (2010)

Sequence analyses of KS domains of Paenibacillus sp. F6‐B70. A. A complete module was deduced from a sequenced fragment between two KS domains. The Kirromycin gene cluster was used as the reference as it contains both cis‐ and trans‐AT PKSs (Weber et al., 2008). B. Neighbour‐joining cladogram of KS domains. Bars indicate 10% amino acid sequence divergence. KS numbering refers to the position within the gene cluster starting from the upstream end. The cis‐AT KS3 and KS5 from the erythromycin PKS was used as outgroup. Clade types were shown in roman numbers together with the main substrate type (detailed in Nguyen et al., 2008). The accession numbers of sequences from GenBank database are Bae KS2, ABS74061; Bae KS6, ABS74062; Bae KS12, ABS74064; Dif KS3, ABS74564; Dif KS9, ABS74561; Dif KS14, ABS74558; Ery KS3, AAV51821; Ery KS5, AAV51822; Mln KS3, ABS73797; Mmp KS6, AAM12913; Onn KS3, AAV97870; Ta KS8, ABF92489. Abbreviations: Bae, bacillaene; Dif, difficidin; Mmp, mupirocin; Mln, macrolactin; Onn, onnamide; Ta, myxovirescin.
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Related In: Results  -  Collection

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f2: Sequence analyses of KS domains of Paenibacillus sp. F6‐B70. A. A complete module was deduced from a sequenced fragment between two KS domains. The Kirromycin gene cluster was used as the reference as it contains both cis‐ and trans‐AT PKSs (Weber et al., 2008). B. Neighbour‐joining cladogram of KS domains. Bars indicate 10% amino acid sequence divergence. KS numbering refers to the position within the gene cluster starting from the upstream end. The cis‐AT KS3 and KS5 from the erythromycin PKS was used as outgroup. Clade types were shown in roman numbers together with the main substrate type (detailed in Nguyen et al., 2008). The accession numbers of sequences from GenBank database are Bae KS2, ABS74061; Bae KS6, ABS74062; Bae KS12, ABS74064; Dif KS3, ABS74564; Dif KS9, ABS74561; Dif KS14, ABS74558; Ery KS3, AAV51821; Ery KS5, AAV51822; Mln KS3, ABS73797; Mmp KS6, AAM12913; Onn KS3, AAV97870; Ta KS8, ABF92489. Abbreviations: Bae, bacillaene; Dif, difficidin; Mmp, mupirocin; Mln, macrolactin; Onn, onnamide; Ta, myxovirescin.
Mentions: For PKS, 22 independent clones were sequenced and only four different nucleotide sequences were obtained (Table 1). The deduced amino acid sequences of these four unique DNA fragments were highly related (72.6–77.7% identity) to known trans‐AT PKS sequences, suggesting that F6‐B70 hosts trans‐AT PKSs. To verify the structure of PKS in F6‐B70, the primers derived from two independent KS domains were used to amplify DNA fragments in between and a 4209 bp fragment was obtained. Sequence alignment with representative PKS clusters revealed that the fragment contains five domains, including two KS, one dehydratase (DH), one ketoreductase and one ACP (Fig. 2A) (Weber et al., 2008), confirming that strain F6‐B70 contains trans‐PKS. It has been reported that the ∼230‐amino‐acid internal region of KS domains generated by PCR was sufficient to provide structural information (Nguyen et al., 2008). We thus constructed a phylogenetic tree using a neighbour‐joining algorithm based on the unique PKS sequences of F6‐B70 and the closest homologues. As shown in Fig. 2B, all of these four KS sequences were clustered into trans‐AT PKSs clades, indicating that F6‐B70 hosts trans‐AT PKSs. Three KS sequences, PKSI‐3, PKSI‐4 and PKSI‐5, belong to clade I, implicating a branched substrate. On the contrary, PKSI‐2 was grouped into the single‐bond subclade of clade V, suggesting that the substrate may contain a single bond between two specific carbons.

Bottom Line: Elucidation of the structure by nuclear magnetic resonance and infrared spectroscopy revealed that the active compound, paenimacrolidin (PAM), was a novel 22-membered macrolide with side-chains.The antibiotic capacity of PAM was compromised by its instability, which can be overcome significantly with addition of an anti-oxidant.To our knowledge, this is the first report of the isolation of an active macrolide from paenibacilli, which may be a promising source of novel antibiotics.

View Article: PubMed Central - PubMed

Affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China. mblab@163.com

Show MeSH
Related in: MedlinePlus