Identification of NanE as the thioesterase for polyether chain release in nanchangmycin biosynthesis.
The polyketide synthase (PKS) for the biosynthesis of the polyether nanchangmycin lacks an apparent thioesterase comparable to the type I thioesterase domains of the modular PKSs responsible for macrolide biosynthesis. Three candidate polyether chain-releasing factors were examined. Both the putative CR domain and the NanE protein appeared to be genetically relevant. Among the three heterologously expressed soluble proteins (recombinant CR domain, the ACP-CR didomain, and NanE) tested, only NanE hydrolyzed the polyether-SNAC. By contrast, recombinant DEBS TE from the erythromycin pathway, and the recombinant MonAX, a type II TE associated with the polyether monensin biosynthesis for which a homolog has not been detected in the nanchangmycin cluster, hydrolyzed a diketide-SNAC but not the polyether-SNAC. We could thus conclude that NanE is a dedicated thioesterase mediating the specific release of the polyether chain during nanchangmycin biosynthesis.
Liu
Tiangang
T
Laboratory of Microbial Metabolism and School of Life Science & Biotechnology, Shanghai Jiaotong University, Shanghai 200030, China.
You
Delin
D
Valenzano
Chiara
C
Sun
Yuhui
Y
Li
Jialiang
J
Yu
Qing
Q
Zhou
Xiufen
X
Cane
David E
DE
Deng
Zixin
Z
D000595:Amino Acid Sequence; D002853:Chromatography, Liquid; D004987:Ethers / Q000737:chemistry / Q000378:metabolism*; D017353:Gene Deletion; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D048630:Polyketide Synthases / Q000737:chemistry* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D013141:Spiro Compounds / Q000737:chemistry / Q000378:metabolism*; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics; D013869:Thiolester Hydrolases / Q000737:chemistry* / Q000378:metabolism*
D004987:Ethers; D011994:Recombinant Proteins; D013141:Spiro Compounds; C452419:nanchangmycin; D048630:Polyketide Synthases; D013869:Thiolester Hydrolases