alr0882 encoding a hypothetical protein of Anabaena PCC7120 protects Escherichia coli from nutrient starvation and abiotic stresses

Gene ◽  
2012 ◽  
Vol 511 (2) ◽  
pp. 248-255 ◽  
Author(s):  
Alok Kumar Shrivastava ◽  
Sarita Pandey ◽  
Prashant Kumar Singh ◽  
Snigdha Rai ◽  
Lal Chand Rai
Keyword(s):  
Escherichia Coli ◽  
Abiotic Stresses ◽  
Hypothetical Protein ◽  
Nutrient Starvation ◽  
Anabaena Pcc7120

scholarly journals Isolation of a Gene Responsible for the Oxidation oftrans-Anethole topara-Anisaldehyde by Pseudomonas putida JYR-1 and Its Expression in Escherichia coli

2012 ◽  
Vol 78 (15) ◽  
pp. 5238-5246 ◽  
Author(s):  
Dongfei Han ◽  
Ji-Young Ryu ◽  
Robert A. Kanaly ◽  
Hor-Gil Hur
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Putida ◽  
Hypothetical Protein ◽  
Aldehyde Group ◽  
Agrobacterium Vitis ◽  
T7 Promoter ◽  
Content Type ◽  
E Coli ◽  
Cell Extracts ◽  
Isoeugenol Monooxygenase

ABSTRACTA plasmid, pTA163, inEscherichia colicontained an approximately 34-kb gene fragment fromPseudomonas putidaJYR-1 that included the genes responsible for the metabolism oftrans-anethole to protocatechuic acid. Three Tn5-disrupted open reading frame 10 (ORF 10) mutants of plasmid pTA163 lost their abilities to catalyzetrans-anethole. Heterologously expressed ORF 10 (1,047 nucleotides [nt]) under a T7 promoter inE. colicatalyzed oxidative cleavage of a propenyl group oftrans-anethole to an aldehyde group, resulting in the production ofpara-anisaldehyde, and this gene was designatedtao(trans-anetholeoxygenase). The deduced amino acid sequence of TAO had the highest identity (34%) to a hypothetical protein ofAgrobacterium vitisS4 and likely contained a flavin-binding site. Preferred incorporation of an oxygen molecule from water intop-anisaldehyde using18O-labeling experiments indicated stereo preference of TAO for hydrolysis of the epoxide group. Interestingly, unlike the narrow substrate range of isoeugenol monooxygenase fromPseudomonas putidaIE27 andPseudomonas nitroreducensJin1, TAO fromP. putidaJYR-1 catalyzed isoeugenol,O-methyl isoeugenol, and isosafrole, all of which contain the 2-propenyl functional group on the aromatic ring structure. Addition of NAD(P)H to the ultrafiltered cell extracts ofE. coli(pTA163) increased the activity of TAO. Due to the relaxed substrate range of TAO, it may be utilized for the production of various fragrance compounds from plant phenylpropanoids in the future.

Crystal structure of YIGZ, a conserved hypothetical protein from Escherichia coli k12 with a novel fold

2004 ◽  
Vol 55 (3) ◽  
pp. 775-777 ◽  
Author(s):  
Frances Park ◽  
Ketan Gajiwala ◽  
Galina Eroshkina ◽  
Eva Furlong ◽  
Dongmei He ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Escherichia Coli ◽  
Hypothetical Protein ◽  
Escherichia Coli K12

scholarly journals The adaptive response to long-term nitrogen starvation in Escherichia coli requires the breakdown of allantoin

2020 ◽  
Author(s):  
Amy Switzer ◽  
Lynn Burchell ◽  
Josh McQuail ◽  
Sivaramesh Wigneshweraraj
Keyword(s):  
Escherichia Coli ◽  
Cell Function ◽  
Nitrogen Starvation ◽  
Nutrient Starvation ◽  
Continuous Growth ◽  
E Coli ◽  
Transcriptional Changes ◽  
N Starvation ◽  
Over Time

ABSTRACTBacteria initially respond to nutrient starvation by eliciting large-scale transcriptional changes. The accompanying changes in gene expression and metabolism allow the bacterial cells to effectively adapt to the nutrient starved state. How the transcriptome subsequently changes as nutrient starvation ensues is not well understood. We used nitrogen (N) starvation as a model nutrient starvation condition to study the transcriptional changes in Escherichia coli experiencing long-term N starvation. The results reveal that the transcriptome of N starved E. coli undergoes changes that are required to maximise chances of viability and to effectively recover growth when N starvation conditions become alleviated. We further reveal that, over time, N starved E. coli cells rely on the degradation of allantoin for optimal growth recovery when N becomes replenished. This study provides insights into the temporally coordinated adaptive responses that occur in E. coli experiencing sustained N starvation.IMPORTANCEBacteria in their natural environments seldom encounter conditions that support continuous growth. Hence, many bacteria spend the majority of their time in states of little or no growth due to starvation of essential nutrients. To cope with prolonged periods of nutrient starvation, bacteria have evolved several strategies, primarily manifesting themselves through changes in how the information in their genes is accessed. How these coping strategies change over time under nutrient starvation is not well understood and this knowledge is not only important to broaden our understanding of bacterial cell function, but also to potentially find ways to manage harmful bacteria. This study provides insights into how nitrogen starved Escherichia coli bacteria rely on different genes during long term nitrogen starvation.

scholarly journals Mutational Analysis of the RecJ Exonuclease ofEscherichia coli: Identification of Phosphoesterase Motifs

1999 ◽  
Vol 181 (19) ◽  
pp. 6098-6102 ◽  
Author(s):  
Vincent A. Sutera ◽  
Eugene S. Han ◽  
Luis A. Rajman ◽  
Susan T. Lovett
Keyword(s):  
Escherichia Coli ◽  
Mutational Analysis ◽  
Large Family ◽  
High Specificity ◽  
Hypothetical Protein ◽  
Mismatch Repair Genes ◽  
E Coli ◽  
Genes Encoding ◽  
Base Excision ◽  
Repair Genes

ABSTRACT The recJ gene, identified in Escherichia coli, encodes a Mg+2-dependent 5′-to-3′ exonuclease with high specificity for single-strand DNA. Genetic and biochemical experiments implicate RecJ exonuclease in homologous recombination, base excision, and methyl-directed mismatch repair. Genes encoding proteins with strong similarities to RecJ have been found in every eubacterial genome sequenced to date, with the exception ofMycoplasma and Mycobacterium tuberculosis. Multiple genes encoding proteins similar to RecJ are found in some eubacteria, including Bacillus andHelicobacter, and in the archaea. Among this divergent set of sequences, seven conserved motifs emerge. We demonstrate here that amino acids within six of these motifs are essential for both the biochemical and genetic functions of E. coli RecJ. These motifs may define interactions with Mg2+ ions or substrate DNA. A large family of proteins more distantly related to RecJ is present in archaea, eubacteria, and eukaryotes, including a hypothetical protein in the MgPa adhesin operon ofMycoplasma, a domain of putative polyA polymerases inSynechocystis and Aquifex, PRUNE ofDrosophila, and an exopolyphosphatase (PPX1) ofSaccharomyces cereviseae. Because these six RecJ motifs are shared between exonucleases and exopolyphosphatases, they may constitute an ancient phosphoesterase domain now found in all kingdoms of life.

scholarly journals Characterization of Extended-Spectrum β-Lactamase Genes Found among Escherichia coli Isolates from Duck and Environmental Samples Obtained on a Duck Farm

2012 ◽  
Vol 78 (10) ◽  
pp. 3668-3673 ◽  
Author(s):  
Junying Ma ◽  
Jian-Hua Liu ◽  
Luchao Lv ◽  
Zhiyong Zong ◽  
Yan Sun ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Environmental Samples ◽  
Genetic Relatedness ◽  
Antibiotic Resistance Genes ◽  
Hypothetical Protein ◽  
M Gene ◽  
Content Type ◽  
E Coli ◽  
Extended Spectrum

ABSTRACTIn this study, we focused on evaluating the occurrence of extended-spectrum β-lactamase (ESBL)-producingEscherichia coliin fecal samples of healthy ducks and environmental samples from a duck farm in South China. Duck cloacal swabs and pond water samples were cultivated on MacConkey agar plates supplemented with ceftiofur. Individual colonies were examined for ESBL production. Bacteria identified asE. coliwere screened for the presence of ESBL and plasmid-borne AmpC genes. The genetic relatedness, plasmid replicon type, and genetic background were determined. Of 245 samples analyzed, 123 hadE. coliisolates with ceftiofur MICs higher than 8 μg/ml (116 [50.4%] from 230 duck samples and 7 [46.7%] from 15 water samples).blaCTX-M,blaSHV-12,blaCMY-2, andblaDHA-1were identified in 108, 5, 9, and 1 isolates, respectively. The most commonblaCTX-Mgenes wereblaCTX-M-27(n= 34),blaCTX-M-55(n= 27),blaCTX-M-24e(n= 22), andblaCTX-M-105(n= 20), followed byblaCTX-M-14a,blaCTX-M-14b,blaCTX-M-24a, andblaCTX-M-24b. Although most of the CTX-M producers had distinct pulsotypes, clonal transmission between duck and water isolates was observed.blaCTX-Mgenes were carried by transferable IncN, IncF, and untypeable plasmids. The novel CTX-M geneblaCTX-M-105was flanked by two hypothetical protein sequences, partial ISEcp1upstream and truncated IS903D,iroN,orf1, and a Tn1721-like element downstream. It is suggested that the horizontal transfer ofblaCTX-Mgenes mediated by mobile elements and the clonal spread of CTX-M-producingE. coliisolates contributed to the dissemination ofblaCTX-Min the duck farm. Our findings highlight the importance of ducks for the dissemination of transferable antibiotic resistance genes into the environment.

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