Several genetically stable mutants blocked in nikkomycin biosynthesis were obtained after the slightly germinated spores of Streptomyces ansochromogenes, a nikkomycin producer, were treated with ultra violet radiation...Several genetically stable mutants blocked in nikkomycin biosynthesis were obtained after the slightly germinated spores of Streptomyces ansochromogenes, a nikkomycin producer, were treated with ultra violet radiation. One of the mutants is the same in morpholotical differentiation as the wild type strain and is designated as NBB19. A DMA library was constructed using plasmid plJ702 as cloning vector, NBB19 as cloning recipient. A 6 kb DNA fragment which can genetically complement NBB19 was cloned when screening the library for antifungal activity. Sequence analysis showed that the 3 kb Bgl II-Sal I fragment contains one complete ORF (ORF1) and one partial ORF (ORF2). ORF1 is designated as sanA. sanA is 1 365 bp, encoding a protein consisting of 454 amino acid residues. Database searching indicated that sanA is homologous to the hypothetical methyltransferase in Pyrococcus horikoshli with 25% identities and 41% positives. Disruptant of sanA lost the ability to synthesize nikkomycin. It indicated that sanA is a novel gene which is essential for nikkomycin biosynthesis.展开更多
A 6.0 kb DNA fragment related to nikkomycin biosynthesis was cloned from nikkomycin-producing Streptomyces ansochromogenes 7100. Sequence analysis showed that the 1.9 kb Tth111 I fragment, a part of the 6.0 kb DNA fra...A 6.0 kb DNA fragment related to nikkomycin biosynthesis was cloned from nikkomycin-producing Streptomyces ansochromogenes 7100. Sequence analysis showed that the 1.9 kb Tth111 I fragment, a part of the 6.0 kb DNA fragment, contains one complete ORF designated sanB (GenBank accession No. AF224501), which is composed of 1740 bp encoding a protein consisting of 580 amino acid residues. Its start codon is GTG at 100 bp position and stop codon is TGA at 1840-bp position. Database searching indicated that the deduced protein of sanB is homologous to the histidinol-phosphate aminotransferase in Streptomyces coelicolor with 31% identities and 47% positives. Gene disruption was performed to study the function of sanB. It was found that disruptants of sanB lost the ability to synthesize nikkomycin, which reveals that sanB is a novel gene essential for nikkomycin biosynthesis.展开更多
Chitin synthase(CHS)is a potential agricultural and therapeutic target.Recently,the crystal structures of CHS from Phytophthora sojae(PsChs1)and Candida albicans(CaChs2)were reported.Here,we highlight the achievements...Chitin synthase(CHS)is a potential agricultural and therapeutic target.Recently,the crystal structures of CHS from Phytophthora sojae(PsChs1)and Candida albicans(CaChs2)were reported.Here,we highlight the achievements of PsChs1 and CaChs2,which would give some clues for design new inhibitor targeted upon CHS.展开更多
文摘Several genetically stable mutants blocked in nikkomycin biosynthesis were obtained after the slightly germinated spores of Streptomyces ansochromogenes, a nikkomycin producer, were treated with ultra violet radiation. One of the mutants is the same in morpholotical differentiation as the wild type strain and is designated as NBB19. A DMA library was constructed using plasmid plJ702 as cloning vector, NBB19 as cloning recipient. A 6 kb DNA fragment which can genetically complement NBB19 was cloned when screening the library for antifungal activity. Sequence analysis showed that the 3 kb Bgl II-Sal I fragment contains one complete ORF (ORF1) and one partial ORF (ORF2). ORF1 is designated as sanA. sanA is 1 365 bp, encoding a protein consisting of 454 amino acid residues. Database searching indicated that sanA is homologous to the hypothetical methyltransferase in Pyrococcus horikoshli with 25% identities and 41% positives. Disruptant of sanA lost the ability to synthesize nikkomycin. It indicated that sanA is a novel gene which is essential for nikkomycin biosynthesis.
文摘A 6.0 kb DNA fragment related to nikkomycin biosynthesis was cloned from nikkomycin-producing Streptomyces ansochromogenes 7100. Sequence analysis showed that the 1.9 kb Tth111 I fragment, a part of the 6.0 kb DNA fragment, contains one complete ORF designated sanB (GenBank accession No. AF224501), which is composed of 1740 bp encoding a protein consisting of 580 amino acid residues. Its start codon is GTG at 100 bp position and stop codon is TGA at 1840-bp position. Database searching indicated that the deduced protein of sanB is homologous to the histidinol-phosphate aminotransferase in Streptomyces coelicolor with 31% identities and 47% positives. Gene disruption was performed to study the function of sanB. It was found that disruptants of sanB lost the ability to synthesize nikkomycin, which reveals that sanB is a novel gene essential for nikkomycin biosynthesis.
基金supported in part by the National Key Research and Development Program of China(2022YFD1700204).
文摘Chitin synthase(CHS)is a potential agricultural and therapeutic target.Recently,the crystal structures of CHS from Phytophthora sojae(PsChs1)and Candida albicans(CaChs2)were reported.Here,we highlight the achievements of PsChs1 and CaChs2,which would give some clues for design new inhibitor targeted upon CHS.
