scholarly journals Genetic Characterization of the Resorcinol Catabolic Pathway in Corynebacterium glutamicum

2006 ◽  
Vol 72 (11) ◽  
pp. 7238-7245 ◽  
Author(s):  
Yan Huang ◽  
Ke-Xin Zhao ◽  
Xi-Hui Shen ◽  
Muhammad Tausif Chaudhry ◽  
Cheng-Ying Jiang ◽  
...  
Keyword(s):  
Corynebacterium Glutamicum ◽  
Genetic Characterization ◽  
Gene Clusters ◽  
Sole Source ◽  
Cloning And Expression ◽  
Catabolic Pathway ◽  
E Coli ◽  
Genome Wide ◽  
Genome Wide Data

ABSTRACT Corynebacterium glutamicum grew on resorcinol as a sole source of carbon and energy. By genome-wide data mining, two gene clusters, designated NCgl1110-NCgl1113 and NCgl2950-NCgl2953, were proposed to encode putative proteins involved in resorcinol catabolism. Deletion of the NCgl2950-NCgl2953 gene cluster did not result in any observable phenotype changes. Disruption and complementation of each gene at NCgl1110-NCgl1113, NCgl2951, and NCgl2952 indicated that these genes were involved in resorcinol degradation. Expression of NCgl1112, NCgl1113, and NCgl2951 in Escherichia coli revealed that NCgl1113 and NCgl2951 both coded for hydroxyquinol 1,2-dioxygenases and NCgl1112 coded for maleylacetate reductases. NCgl1111 encoded a putative monooxygenase, but this putative hydroxylase was very different from previously functionally identified hydroxylases. Cloning and expression of NCgl1111 in E. coli revealed that NCgl1111 encoded a resorcinol hydroxylase that needs NADPH as a cofactor. E. coli cells containing Ncgl1111 and Ncgl1113 sequentially converted resorcinol into maleylacetate. NCgl1110 and NCgl2950 both encoded putative TetR family repressors, but only NCgl1110 was transcribed and functional. NCgl2953 encoded a putative transporter, but disruption of this gene did not affect resorcinol degradation by C. glutamicum. The function of NCgl2953 remains unclear.

scholarly journals Functional Identification of Novel Genes Involved in the Glutathione-Independent Gentisate Pathway in Corynebacterium glutamicum

2005 ◽  
Vol 71 (7) ◽  
pp. 3442-3452 ◽  
Author(s):  
Xi-Hui Shen ◽  
Cheng-Ying Jiang ◽  
Yan Huang ◽  
Zhi-Pei Liu ◽  
Shuang-Jiang Liu
Keyword(s):  
Corynebacterium Glutamicum ◽  
Hypothetical Protein ◽  
Cloning And Expression ◽  
Functional Identification ◽  
E Coli ◽  
Transporter Protein ◽  
Genome Wide ◽  
Genes Encoding ◽  
Gentisate Pathway ◽  
Genome Wide Data

ABSTRACT Corynebacterium glutamicum used gentisate and 3-hydroxybenzoate as its sole carbon and energy source for growth. By genome-wide data mining, a gene cluster designated ncg12918-ncg12923 was proposed to encode putative proteins involved in gentisate/3-hydroxybenzoate pathway. Genes encoding gentisate 1,2-dioxygenase (ncg12920) and fumarylpyruvate hydrolase (ncg12919) were identified by cloning and expression of each gene in Escherichia coli. The gene of ncg12918 encoding a hypothetical protein (Ncg12918) was proved to be essential for gentisate-3-hydroxybenzoate assimilation. Mutant strain RES167Δncg12918 lost the ability to grow on gentisate or 3-hydroxybenzoate, but this ability could be restored in C. glutamicum upon the complementation with pXMJ19-ncg12918. Cloning and expression of this ncg12918 gene in E. coli showed that Ncg12918 is a glutathione-independent maleylpyruvate isomerase. Upstream of ncg12920, the genes ncg12921-ncg12923 were located, which were essential for gentisate and/or 3-hydroxybenzoate catabolism. The Ncg12921 was able to up-regulate gentisate 1,2-dioxygenase, maleylpyruvate isomerase, and fumarylpyruvate hydrolase activities. The genes ncg12922 and ncg12923 were deduced to encode a gentisate transporter protein and a 3-hydroxybenzoate hydroxylase, respectively, and were essential for gentisate or 3-hydroxybenzoate assimilation. Based on the results obtained in this study, a GSH-independent gentisate pathway was proposed, and genes involved in this pathway were identified.

scholarly journals Biochemical and Molecular Characterization of theBacillus subtilis Acetoin Catabolic Pathway

1999 ◽  
Vol 181 (12) ◽  
pp. 3837-3841 ◽  
Author(s):  
Min Huang ◽  
Fred Bernd Oppermann-Sanio ◽  
Alexander Steinbüchel
Keyword(s):  
Bacillus Subtilis ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Enzyme System ◽  
Gene Clusters ◽  
Catabolic Pathway ◽  
E Coli ◽  
Homologous Genes ◽  
Dehydrogenase Enzyme

ABSTRACT A recent study indicated that Bacillus subtiliscatabolizes acetoin by enzymes encoded by the acu gene cluster (F. J. Grundy, D. A. Waters, T. Y. Takova, and T. M. Henkin, Mol. Microbiol. 10:259–271, 1993) that are completely different from those in the multicomponent acetoin dehydrogenase enzyme system (AoDH ES) encoded by aco gene clusters found before in all other bacteria capable of utilizing acetoin as the sole carbon source for growth. By hybridization with a DNA probe covering acoA and acoB of the AoDH ES from Clostridium magnum, genomic fragments from B. subtilis harboring acoA, acoB,acoC, acoL, and acoR homologous genes were identified, and some of them were functionally expressed inE. coli. Furthermore, acoA was inactivated inB. subtilis by disruptive mutagenesis; these mutants were impaired to express PPi-dependent AoDH E1 activity to remove acetoin from the medium and to grow with acetoin as the carbon source. Therefore, acetoin is catabolized in B. subtilis by the same mechanism as all other bacteria investigated so far, leaving the function of the previously described acu genes obscure.

scholarly journals Cold shock as a screen for genes involved in cold acclimatization in Neurospora crassa

2018 ◽  
Author(s):  
Michael K. Watters ◽  
Victor Manzanilla ◽  
Holly Howell ◽  
Alexander Mehreteab ◽  
Erik Rose ◽  
...  
Keyword(s):  
Cold Shock ◽  
Genetic Characterization ◽  
Morphological Changes ◽  
Morphological Response ◽  
Significant Percentage ◽  
E Coli ◽  
Cold Environments ◽  
Cold Shock Response ◽  
Shock Response

ABSTRACTWhen subjected to rapid drops of temperature (cold shock), Neurospora responds with a dramatic, but temporary shift in its branching pattern. While the cold shock response has been described morphologically, it has yet to be examined genetically. This project aims to begin the genetic characterization of the cold shock response and the associated acclimatization to cold environments. We report here the results of a screen of mutants from the Neurospora knockout library for alterations in their morphological response to cold shock and thus, their ability to acclimatize to the cold. Three groups of knockouts were selected to be subject to this screen: genes previously suspected to be involved in hyphal development as well as knockouts resulting in morphological changes; transcription factors; and genes homologous to E. coli genes known to alter their expression in response to cold shock. Several strains were identified with altered responses. The genes impacted in these mutants are listed and discussed. A significant percentage (81%) of the knockouts of genes homologous to those previously identified in E. coli showed altered cold shock responses in Neurospora – suggesting that the response in these two organisms is largely shared in common.

scholarly journals Genetic characterization of wild barley populations (Hordeum vulgare ssp. spontaneum) from Kazakhstan based on genome wide SNP analysis

2014 ◽  
Vol 64 (4) ◽  
pp. 399-403 ◽  
Author(s):  
Yerlan Turuspekov ◽  
Saule Abugalieva ◽  
Kanat Ermekbayev ◽  
Kazuhiro Sato
Keyword(s):  
Hordeum Vulgare ◽  
Wild Barley ◽  
Genetic Characterization ◽  
Snp Analysis ◽  
Genome Wide ◽  
Hordeum Vulgare Ssp

Cloning and expression of DiT33 from Dirofilaria immitis: a specific and early marker of heartworm infection

Parasitology ◽  
1996 ◽  
Vol 112 (3) ◽  
pp. 331-338 ◽  
Author(s):  
X. Q. Hong ◽  
J. Santiago Mejia ◽  
S. Kumar ◽  
F. B. Perler ◽  
C. K. S. Carlow
Keyword(s):  
Dirofilaria Immitis ◽  
Cloning And Expression ◽  
E Coli ◽  
Spliced Leader ◽  
Isolation And Characterization ◽  
The Family ◽  
Heartworm Infection ◽  
High Level ◽  
Control And Management

SUMMARYDirofilaria immitis is an important filarial parasite of dogs and cats, and a useful model for human filariasis. Current diagnostic tests for heartworm infection in animals rely on the presence of fecund female worms (usually found 6·5 months post-infection or later) and therefore fail to detect pre-patent infections. Putative pepsin inhibitors from 2 filarial parasites of humans namely Onchocerca volvulus (Ov33, Oc3.6, OvDSB) and Brugia malayi (Bm33), have been shown to be useful in diagnosis of onchocerciasis and lymphatic filariasis, respectively. Previous studies have suggested that a homologue exists in D. immitis (DiT33), which may have potential in diagnosis of heartworm infection. In this study, the isolation and characterization of a cDNA clone encoding DiT33 is described.‡ This cDNA contains 12 bases of the nematode-specific 22 nucleotide spliced leader sequence and encodes a 26·4 kDa-protein with a high level of similarity (87–89%) to other filarial members of the family. DJT33 was over-expressed in E. coli as a fusion with the maltose-binding protein and serological analysis was performed using a panel of clinically defined dog sera. The findings of this study indicate that DiT33 is a promising antigen for the early detection of D. immitis and may be a valuable tool in the control and management of heartworm infection.

scholarly journals In vivo characterization of the activities of novel cyclodipeptide oxidases: new tools for increasing chemical diversity of bioproduced 2,5-diketopiperazines in Escherichia coli

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Fabien Le Chevalier ◽  
Isabelle Correia ◽  
Lucrèce Matheron ◽  
Morgan Babin ◽  
Mireille Moutiez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biological Activities ◽  
Gene Clusters ◽  
Chemical Diversity ◽  
E Coli ◽  
Chemical Structures ◽  
In Vivo Characterization ◽  
Culture Supernatants

Abstract Background Cyclodipeptide oxidases (CDOs) are enzymes involved in the biosynthesis of 2,5-diketopiperazines, a class of naturally occurring compounds with a large range of pharmaceutical activities. CDOs belong to cyclodipeptide synthase (CDPS)-dependent pathways, in which they play an early role in the chemical diversification of cyclodipeptides by introducing Cα-Cβ dehydrogenations. Although the activities of more than 100 CDPSs have been determined, the activities of only a few CDOs have been characterized. Furthermore, the assessment of the CDO activities on chemically-synthesized cyclodipeptides has shown these enzymes to be relatively promiscuous, making them interesting tools for cyclodipeptide chemical diversification. The purpose of this study is to provide the first completely microbial toolkit for the efficient bioproduction of a variety of dehydrogenated 2,5-diketopiperazines. Results We mined genomes for CDOs encoded in biosynthetic gene clusters of CDPS-dependent pathways and selected several for characterization. We co-expressed each with their associated CDPS in the pathway using Escherichia coli as a chassis and showed that the cyclodipeptides and the dehydrogenated derivatives were produced in the culture supernatants. We determined the biological activities of the six novel CDOs by solving the chemical structures of the biologically produced dehydrogenated cyclodipeptides. Then, we assessed the six novel CDOs plus two previously characterized CDOs in combinatorial engineering experiments in E. coli. We co-expressed each of the eight CDOs with each of 18 CDPSs selected for the diversity of cyclodipeptides they synthesize. We detected more than 50 dehydrogenated cyclodipeptides and determined the best CDPS/CDO combinations to optimize the production of 23. Conclusions Our study establishes the usefulness of CDPS and CDO for the bioproduction of dehydrogenated cyclodipeptides. It constitutes the first step toward the bioproduction of more complex and diverse 2,5-diketopiperazines.

scholarly journals Genetic Characterization of Salmonella Infantis with Multiple Drug Resistance Profiles Isolated from a Poultry-Farm in Chile

2021 ◽  
Vol 9 (11) ◽  
pp. 2370
Author(s):  
Coral Pardo-Esté ◽  
Diego Lorca ◽  
Juan Castro-Severyn ◽  
Gabriel Krüger ◽  
Luis Alvarez-Thon ◽  
...  
Keyword(s):  
Production Line ◽  
Core Genome ◽  
Genetic Characterization ◽  
Multiple Drug Resistance ◽  
Gene Clusters ◽  
Poultry Meat ◽  
Health Concern ◽  
Multiple Drug ◽  
Important Health

Salmonella comprises over 2500 serotypes and foodborne contamination associated with this pathogen remains an important health concern worldwide. During the last decade, a shift in serotype prevalence has occurred as traditionally less prevalent serotypes are increasing in frequency of infections, especially those related to poultry meat contamination. S. Infantis is one of the major emerging serotypes, and these strains commonly display antimicrobial resistance and can persist despite cleaning protocols. Thus, this work aimed to isolate S. Infantis strains from a poultry meat farm in Santiago, Chile and to characterize genetic variations present in them. We determined their genomic and phenotypic profiles at different points along the production line. The results indicate that the strains encompass 853 polymorphic sites (core-SNPs) with isolates differing from one another by 0–347 core SNPs, suggesting variation among them; however, we found discrete correlations with the source of the sample in the production line. Furthermore, the pan-genome was composed of 4854 total gene clusters of which 2618 (53.9%) corresponds to the core-genome and only 181 (3.7%) are unique genes (those present in one particular strain). This preliminary analysis will enrich the surveillance of Salmonella, yet further studies are required to assess their evolution and phylogeny.

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