Faculty Opinions recommendation of Expression analysis of the tylosin-biosynthetic gene cluster: pivotal regulatory role of the tylQ product.

2002 ◽  
Author(s):  
Ben Shen
Keyword(s):  
Gene Cluster ◽  
Expression Analysis ◽  
Biosynthetic Gene Cluster ◽  
Regulatory Role ◽  
Biosynthetic Gene

scholarly journals Organization of the biosynthetic gene cluster for the macrolide concanamycin A in Streptomyces neyagawaensis ATCC 27449

Microbiology ◽  
2005 ◽  
Vol 151 (10) ◽  
pp. 3161-3169 ◽  
Author(s):  
Stephen F. Haydock ◽  
Anthony N. Appleyard ◽  
Tatiana Mironenko ◽  
John Lester ◽  
Natasha Scott ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Biosynthetic Pathway ◽  
Polyketide Synthase ◽  
Building Blocks ◽  
Biosynthetic Gene Cluster ◽  
Sequence Motif ◽  
Biosynthetic Gene ◽  
Concanamycin A ◽  
Modular Polyketide Synthase

The macrolide antibiotic concanamycin A has been identified as an exceptionally potent inhibitor of the vacuolar (V-type) ATPase. Such compounds have been mooted as the basis of a potential drug treatment for osteoporosis, since the V-ATPase is involved in the osteoclast-mediated bone resorption that underlies this common condition. To enable combinatorial engineering of altered concanamycins, the biosynthetic gene cluster governing the biosynthesis of concanamycin A has been cloned from Streptomyces neyagawaensis and shown to span a region of over 100 kbp of contiguous DNA. An efficient transformation system has been developed for S. neyagawaensis and used to demonstrate the role of the cloned locus in the formation of concanamycin A. Sequence analysis of the 28 ORFs in the region has revealed key features of the biosynthetic pathway, in particular the biosynthetic origin of portions of the backbone, which arise from the unusual polyketide building blocks ethylmalonyl-CoA and methoxymalonyl-ACP, and the origin of the pendant deoxysugar moiety 4′-O-carbamoyl-2′-deoxyrhamnose, as well as the presence of a modular polyketide synthase (PKS) encoded by six giant ORFs. Examination of the methoxymalonyl-specific acyltransferase (AT) domains has led to recognition of an amino acid sequence motif which can be used to distinguish methylmalonyl-CoA- from methoxymalonyl-ACP-specific AT domains in natural PKSs.

scholarly journals Trichoderma reesei Contains a Biosynthetic Gene Cluster That Encodes the Antifungal Agent Ilicicolin H

2021 ◽  
Vol 7 (12) ◽  
pp. 1034
Author(s):  
Mary L. Shenouda ◽  
Maria Ambilika ◽  
Russell J. Cox
Keyword(s):  
Cytochrome P450 ◽  
Gene Cluster ◽  
Trichoderma Reesei ◽  
Antifungal Agent ◽  
Biosynthetic Gene Cluster ◽  
Biosynthetic Gene ◽  
Fungal Host ◽  
Tetramic Acids ◽  
New Compounds

The trili biosynthetic gene cluster (BGC) from the well-studied organism Trichoderma reesei was studied by heterologous expression in the fungal host Aspergillus oryzae. Coexpression of triliA and triliB produces two new acyl tetramic acids. Addition of the ring-expanding cytochrome P450 encoded by triliC then yields a known pyridone intermediate to ilicicolin H and a new chain-truncated shunt metabolite. Finally, addition of the intramolecular Diels-Alderase encoded by triliD affords a mixture of 8-epi ilicicolin H and ilicicolin H itself, showing that the T. reesei trili BGC encodes biosynthesis of this potent antifungal agent. Unexpected A. oryzae shunt pathways are responsible for the production of the new compounds, emphasising the role of fungal hosts in catalysing diversification reactions.

scholarly journals Mutational Analysis of nocK and nocL in the Nocardicin A Producer Nocardia uniformis

2005 ◽  
Vol 187 (2) ◽  
pp. 739-746 ◽  
Author(s):  
Wendy L. Kelly ◽  
Craig A. Townsend
Keyword(s):  
Natural Products ◽  
Gene Cluster ◽  
Mutational Analysis ◽  
Biosynthetic Gene Cluster ◽  
Biosynthetic Gene ◽  
Wild Type ◽  
Nocardicin A ◽  
Lactam Ring ◽  
Undetermined Function

ABSTRACT The nocardicins are a family of monocyclic β-lactam antibiotics produced by the actinomycete Nocardia uniformis subsp. tsuyamanensis ATCC 21806. The most potent of this series is nocardicin A, containing a syn-configured oxime moiety, an uncommon feature in natural products. The nocardicin A biosynthetic gene cluster was recently identified and found to encode proteins in keeping with nocardicin A production, including the nocardicin N-oxygenase, NocL, in addition to genes of undetermined function, such as nocK, which bears similarities to a broad family of esterases. The latter was hypothesized to be involved in the formation of the critical β-lactam ring. While previously shown to effect oxidation of the 2′-amine of nocardicin C to provide nocardicin A, it was uncertain whether NocL was the only N-oxidizing enzyme required for nocardicin A biosynthesis. To further detail the role of NocL in nocardicin production in N. uniformis, and to examine the function of nocK, a method for the transformation of N. uniformis protoplasts to inactivate both nocK and nocL was developed and applied. A reliable protocol is reported to achieve both insertional disruption and in trans complementation in this strain. While the nocK mutant still produced nocardicin A at levels near that seen for wild-type N. uniformis, and therefore has no obvious role in nocardicin biosynthesis, the nocL disruptant failed to generate the oxime-containing metabolite. Nocardicin A production was restored in the nocL mutant upon in trans expression of the gene. Furthermore, the nocL mutant accumulated the biosynthetic intermediate nocardicin C, confirming its role as the sole oxime-forming enzyme required for production of nocardicin A.

scholarly journals The role of the TetR-family transcriptional regulator Aur1R in negative regulation of the auricin gene cluster in Streptomyces aureofaciens CCM 3239

Microbiology ◽  
2010 ◽  
Vol 156 (8) ◽  
pp. 2374-2383 ◽  
Author(s):  
Renata Novakova ◽  
Peter Kutas ◽  
Lubomira Feckova ◽  
Jan Kormanec
Keyword(s):  
Gene Cluster ◽  
Biosynthetic Gene Cluster ◽  
Transcriptional Repressors ◽  
Biosynthetic Gene ◽  
Response Regulators ◽  
Streptomyces Aureofaciens ◽  
Two Component Signal Transduction

Two regulatory genes, aur1P and aur1R, have been previously identified upstream of the aur1 polyketide gene cluster involved in biosynthesis of the angucycline-like antibiotic auricin in Streptomyces aureofaciens CCM 3239. The aur1P gene encodes a protein similar to the response regulators of bacterial two-component signal transduction systems and has been shown to specifically activate expression of the auricin biosynthetic genes. The aur1R gene encodes a protein homologous to transcriptional repressors of the TetR family. Here we describe the characterization of the aur1R gene. Expression of the gene is directed by a single promoter, aur1Rp, which is induced just before stationary phase. Disruption of aur1R in S. aureofaciens CCM 3239 had no effect on growth and differentiation. However, the disrupted strain produced more auricin than its parental wild-type S. aureofaciens CCM 3239 strain. Transcription from the aur1Ap and aur1Pp promoters, directing expression of the first biosynthetic gene in the auricin gene cluster and the pathway-specific transcriptional activator, respectively, was increased in the S. aureofaciens CCM 3239 aur1R mutant strain. However, Aur1R was shown to bind specifically only to the aur1Pp promoter in vitro. This binding was abolished by the addition of auricin and/or its intermediates. The results indicate that the Aur1R regulator specifically represses expression of the aur1P gene, which encodes a pathway-specific activator of the auricin biosynthetic gene cluster in S. aureofaciens CCM 3239, and that this repression is relieved by auricin or its intermediates.

scholarly journals Glycosylation Steps during Spiramycin Biosynthesis in Streptomyces ambofaciens: Involvement of Three Glycosyltransferases and Their Interplay with Two Auxiliary Proteins

2010 ◽  
Vol 54 (7) ◽  
pp. 2830-2839 ◽  
Author(s):  
Hoang Chuong Nguyen ◽  
Fatma Karray ◽  
Sylvie Lautru ◽  
Josette Gagnat ◽  
Ahmed Lebrihi ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Polyketide Synthase ◽  
Macrolide Antibiotic ◽  
Biosynthetic Gene Cluster ◽  
Type I ◽  
Biosynthetic Gene ◽  
Streptomyces Ambofaciens ◽  
Mutant Strains ◽  
Genes Encoding

ABSTRACT Streptomyces ambofaciens synthesizes spiramycin, a 16-membered macrolide antibiotic used in human medicine. The spiramycin molecule consists of a polyketide lactone ring (platenolide) synthesized by a type I polyketide synthase, to which three deoxyhexoses (mycaminose, forosamine, and mycarose) are attached successively in this order. These sugars are essential to the antibacterial activity of spiramycin. We previously identified four genes in the spiramycin biosynthetic gene cluster predicted to encode glycosyltransferases. We individually deleted each of these four genes and showed that three of them were required for spiramycin biosynthesis. The role of each of the three glycosyltransferases in spiramycin biosynthesis was determined by identifying the biosynthetic intermediates accumulated by the corresponding mutant strains. This led to the identification of the glycosyltransferase responsible for the attachment of each of the three sugars. Moreover, two genes encoding putative glycosyltransferase auxiliary proteins were also identified in the spiramycin biosynthetic gene cluster. When these two genes were deleted, one of them was found to be dispensable for spiramycin biosynthesis. However, analysis of the biosynthetic intermediates accumulated by mutant strains devoid of each of the auxiliary proteins (or of both of them), together with complementation experiments, revealed the interplay of glycosyltransferases with the auxiliary proteins. One of the auxiliary proteins interacted efficiently with the two glycosyltransferases transferring mycaminose and forosamine while the other auxiliary protein interacted only with the mycaminosyltransferase.

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