Identification and functional analysis of the fusaricidin biosynthetic gene of Paenibacillus polymyxa E681.
Fusaricidin, a peptide antibiotic consisting of six amino acids, has been identified as a potential antifungal agent from Paenibacillus polymyxa. Here, we report the complete sequence of the fusaricidin synthetase gene (fusA) identified from the genome sequence of a rhizobacterium, P. polymyxa E681. The gene encodes a polypeptide consisting of six modules in a single open-reading frame. Interestingly, module six of FusA does not contain an epimerization domain, which suggests that the sixth amino acids of the fusaricidin analogs produced by P. polymyxa E681 may exist as an l-form, although all reported fusaricidins contain d-form alanines in their sixth amino acid residues. Alternatively, the sixth adenylation domain of the FusA may directly recognize the d-form alanine. The inactivation of fusA led to the complete loss of antifungal activity against Fusarium oxysporum. LC/MS analysis confirmed the incapability of fusaricidin production in the fusA mutant strain, thus demonstrating that fusA is involved in fusaricidin biosynthesis. Our findings suggested that FusA can produce more than one kind of fusaricidin, as various forms of fusaricidins were identified from P. polymyxa E681.
Choi
Soo-Keun
SK
Systems Microbiology Research Center, KRIBB, 111 Gwahangno, Yuseong-gu, Daejeon 305-806, Republic of Korea.
Park
Soo-Young
SY
Kim
Rumi
R
Lee
Choong-Hwan
CH
Kim
Jihyun F
JF
Park
Seung-Hwan
SH
D000935:Antifungal Agents / Q000096:biosynthesis* / Q000737:chemistry; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry; D047630:Depsipeptides / Q000096:biosynthesis* / Q000737:chemistry; D005798:Genes, Bacterial; D008957:Models, Genetic
D000935:Antifungal Agents; D001426:Bacterial Proteins; D047630:Depsipeptides; C099200:fusaricidin A