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

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.

Microbiology ◽  
2005 ◽  
Vol 151 (8) ◽  
pp. 2693-2706 ◽  
Author(s):  
Renata Novakova ◽  
Dagmar Homerova ◽  
Lubomira Feckova ◽  
Jan Kormanec

A gene, aur1P, encoding a protein similar to the response regulators of bacterial two-component signal transduction systems, was identified upstream of the aur1 polyketide gene cluster involved in biosynthesis of the angucycline-like antibiotic auricin in Streptomyces aureofaciens CCM 3239. Expression of the gene was directed by a single promoter, aur1Pp, which was transcribed at low levels during the exponential phase and induced just before the stationary phase. A divergently transcribed gene, aur1R, has been identified upstream of aur1P, encoding a protein homologous to transcriptional repressors of the TetR family. The aur1P gene was disrupted in the S. aureofaciens CCM 3239 chromosome by homologous recombination. The mutation in the aur1P gene had no effect on growth and differentiation. However, biochromatographic analysis of culture extracts from the S. aureofaciens aur1P-disrupted strain revealed that auricin was not produced in the mutant. This indicated that aur1P is essential for auricin production. Transcription from the previously characterized aur1Ap promoter, directing expression of the first gene, aur1A, in the auricin gene cluster, was dramatically decreased in the S. aureofaciens CCM 3239 aur1P mutant strain. Moreover, the Aur1P protein, overproduced in Escherichia coli, was shown to bind specifically upstream of the aur1Ap promoter region. The results indicated that the Aur1P regulator activates expression of the auricin biosynthesis genes.


2020 ◽  
Vol 117 (19) ◽  
pp. 10265-10270
Author(s):  
Daan Ren ◽  
Mark W. Ruszczycky ◽  
Yeonjin Ko ◽  
Shao-An Wang ◽  
Yasushi Ogasawara ◽  
...  

Coformycin and pentostatin are structurally related N-nucleoside inhibitors of adenosine deaminase characterized by an unusual 1,3-diazepine nucleobase. Herein, the cof gene cluster responsible for coformycin biosynthesis is identified. Reconstitution of the coformycin biosynthetic pathway in vitro demonstrates that it overlaps significantly with the early stages of l-histidine biosynthesis. Committed entry into the coformycin pathway takes place via conversion of a shared branch point intermediate to 8-ketocoformycin-5′-monophosphate catalyzed by CofB, which is a homolog of succinylaminoimidazolecarboxamide ribotide (SAICAR) synthetase. This reaction appears to proceed via a Dieckmann cyclization and a retro-aldol elimination, releasing ammonia and D-erythronate-4-phosphate as coproducts. Completion of coformycin biosynthesis involves reduction and dephosphorylation of the CofB product, with the former reaction being catalyzed by the NADPH-dependent dehydrogenase CofA. CofB also shows activation by adenosine triphosphate (ATP) despite the reaction requiring neither a phosphorylated nor an adenylated intermediate. This may serve to help regulate metabolic partitioning between the l-histidine and coformycin pathways.


Gene ◽  
2001 ◽  
Vol 278 (1-2) ◽  
pp. 107-114 ◽  
Author(s):  
Antonella Morea ◽  
Kalai Mathee ◽  
Michael J. Franklin ◽  
Alessio Giacomini ◽  
Michael O'Regan ◽  
...  

Gene ◽  
1990 ◽  
Vol 90 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Danila Limauro ◽  
Alessandra Avitabile ◽  
Carmela Cappellano ◽  
Anna Maria Puglia ◽  
Carmelo B. Bruni

2002 ◽  
Vol 267 (5) ◽  
pp. 636-646 ◽  
Author(s):  
Y. Abe ◽  
T. Suzuki ◽  
C. Ono ◽  
K. Iwamoto ◽  
M. Hosobuchi ◽  
...  

2013 ◽  
Vol 97 (14) ◽  
pp. 6337-6345 ◽  
Author(s):  
Bijinu Balakrishnan ◽  
Suman Karki ◽  
Shih-Hau Chiu ◽  
Hyun-Ju Kim ◽  
Jae-Won Suh ◽  
...  

2019 ◽  
Vol 17 (3) ◽  
pp. 461-466 ◽  
Author(s):  
Taro Shiraishi ◽  
Makoto Nishiyama ◽  
Tomohisa Kuzuyama

The biosynthetic pathway of the uridine-derived nucleoside antibiotic A-94964 was proposed via in silico analysis coupled with gene deletion experiments.


Sign in / Sign up

Export Citation Format

Share Document