scholarly journals Roles of orf60a and orf61 in Development of Bacteriophages λ and Φ24B

Viruses ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 553 ◽  
Author(s):  
Aleksandra Dydecka ◽  
Bożena Nejman-Faleńczyk ◽  
Sylwia Bloch ◽  
Gracja Topka ◽  
Agnieszka Necel ◽  
...  
Keyword(s):  
Regulatory Elements ◽  
Open Reading Frames ◽  
Host Cells ◽  
Prophage Induction ◽  
Nutrient Media ◽  
Lambdoid Phage ◽  
Evolutionarily Conserved ◽  
Phage Development ◽  
Phage Propagation ◽  
Reading Frames

The exo-xis region of lambdoid bacteriophage genomes contains several established and potential genes that are evolutionarily conserved, but not essential for phage propagation under laboratory conditions. Nevertheless, deletion or overexpression of either the whole exo-xis region and important regulatory elements can significantly influence the regulation of phage development. This report defines specific roles for orf60a and orf61 in bacteriophage λ and Φ24B, a specific Shiga toxin-converting phage with clinical relevance. We observed that mutant phages bearing deletions of orf60a and orf61 impaired two central aspects of phage development: the lysis-versus-lysogenization decision and prophage induction. These effects were more pronounced for phage Φ24B than for λ. Surprisingly, adsorption of phage Φ24B on Escherichia coli host cells was less efficient in the absence of either orf60a or orf61. We conclude that these open reading frames (ORFs) play important, but not essential, roles in the regulation of lambdoid phage development. Although phages can propagate without these ORFs in nutrient media, we suggest that they may be involved in the regulatory network, ensuring optimization of phage development under various environmental conditions.

scholarly journals Translation of ABCE1 Is Tightly Regulated by Upstream Open Reading Frames in Human Colorectal Cells

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 911
Author(s):  
Joana Silva ◽  
Pedro Nina ◽  
Luísa Romão
Keyword(s):  
Translational Regulation ◽  
Regulatory Elements ◽  
Ribosome Profiling ◽  
Leader Sequence ◽  
Open Reading Frames ◽  
Regulatory Function ◽  
Coding Sequence ◽  
Abc Protein ◽  
Upstream Open Reading Frames ◽  
Reading Frames

ATP-binding cassette subfamily E member 1 (ABCE1) belongs to the ABC protein family of transporters; however, it does not behave as a drug transporter. Instead, ABCE1 actively participates in different stages of translation and is also associated with oncogenic functions. Ribosome profiling analysis in colorectal cancer cells has revealed a high ribosome occupancy in the human ABCE1 mRNA 5′-leader sequence, indicating the presence of translatable upstream open reading frames (uORFs). These cis-acting translational regulatory elements usually act as repressors of translation of the main coding sequence. In the present study, we dissect the regulatory function of the five AUG and five non-AUG uORFs identified in the human ABCE1 mRNA 5′-leader sequence. We show that the expression of the main coding sequence is tightly regulated by the ABCE1 AUG uORFs in colorectal cells. Our results are consistent with a model wherein uORF1 is efficiently translated, behaving as a barrier to downstream uORF translation. The few ribosomes that can bypass uORF1 (and/or uORF2) must probably initiate at the inhibitory uORF3 or uORF5 that efficiently repress translation of the main ORF. This inhibitory property is slightly overcome in conditions of endoplasmic reticulum stress. In addition, we observed that these potent translation-inhibitory AUG uORFs function equally in cancer and in non-tumorigenic colorectal cells, which is consistent with a lack of oncogenic function. In conclusion, we establish human ABCE1 as an additional example of uORF-mediated translational regulation and that this tight regulation contributes to control ABCE1 protein levels in different cell environments.

scholarly journals The Nucleotide Sequence of Shiga Toxin (Stx) 2e-Encoding Phage φP27 Is Not Related to Other Stx Phage Genomes, but the Modular Genetic Structure Is Conserved

2002 ◽  
Vol 70 (4) ◽  
pp. 1896-1908 ◽  
Author(s):  
Jürgen Recktenwald ◽  
Herbert Schmidt
Keyword(s):  
Nucleotide Sequence ◽  
Shiga Toxin ◽  
Phage Genome ◽  
Genetic Recombination ◽  
Genome Structure ◽  
Open Reading Frames ◽  
Functional Modules ◽  
Phage Propagation ◽  
Reading Frames ◽  
Lambdoid Phages

ABSTRACT In this study we determined the complete nucleotide sequence of Shiga toxin 2e-encoding bacteriophage φP27, isolated from the Shiga toxin-producing Escherichia coli patient isolate 2771/97. φP27 is integrated as a prophage in the chromosomal yecE gene. This integration generates identity segments of attL and attR sites with lengths of 11 nucleotides. The integrated prophage genome has a size of 42,575 bp. We identified 58 open reading frames (ORFs), each with a length of >150 nucleotides. The deduced proteins of 44 ORFs showed significant homologies to other proteins present in sequence databases, whereas 14 putative proteins did not. For 29 proteins, we could deduce a putative function. Most of these are related to the basic phage propagation cycle. The φP27 genome represents a mosaic composed of genetic elements which are obviously derived from related and unrelated phages. We identified five short linker sequences of 22 to 151 bp in the φP27 sequence which have also been detected in a couple of other lambdoid phages. These linkers are located between functional modules in the phage genome and are thought to play a role in genetic recombination. Although the overall DNA sequence of φP27 is not highly related to other known phages, the data obtained demonstrate a typical lambdoid genome structure.

The positive regulatory function of the 5'-proximal open reading frames in GCN4 mRNA can be mimicked by heterologous, short coding sequences

1988 ◽  
Vol 8 (9) ◽  
pp. 3827-3836
Author(s):  
N P Williams ◽  
P P Mueller ◽  
A G Hinnebusch
Keyword(s):  
Translational Control ◽  
Normal Growth ◽  
Regulatory Elements ◽  
Growth Conditions ◽  
Open Reading Frames ◽  
Regulatory Function ◽  
Yeast Saccharomyces Cerevisiae ◽  
Reading Frame ◽  
Yeast Genes ◽  
Reading Frames

Translational control of GCN4 expression in the yeast Saccharomyces cerevisiae is mediated by multiple AUG codons present in the leader of GCN4 mRNA, each of which initiates a short open reading frame of only two or three codons. Upstream AUG codons 3 and 4 are required to repress GCN4 expression in normal growth conditions; AUG codons 1 and 2 are needed to overcome this repression in amino acid starvation conditions. We show that the regulatory function of AUG codons 1 and 2 can be qualitatively mimicked by the AUG codons of two heterologous upstream open reading frames (URFs) containing the initiation regions of the yeast genes PGK and TRP1. These AUG codons inhibit GCN4 expression when present singly in the mRNA leader; however, they stimulate GCN4 expression in derepressing conditions when inserted upstream from AUG codons 3 and 4. This finding supports the idea that AUG codons 1 and 2 function in the control mechanism as translation initiation sites and further suggests that suppression of the inhibitory effects of AUG codons 3 and 4 is a general consequence of the translation of URF 1 and 2 sequences upstream. Several observations suggest that AUG codons 3 and 4 are efficient initiation sites; however, these sequences do not act as positive regulatory elements when placed upstream from URF 1. This result suggests that efficient translation is only one of the important properties of the 5' proximal URFs in GCN4 mRNA. We propose that a second property is the ability to permit reinitiation following termination of translation and that URF 1 is optimized for this regulatory function.

scholarly journals Sequence and Organization of pXO1, the Large Bacillus anthracis Plasmid Harboring the Anthrax Toxin Genes

1999 ◽  
Vol 181 (20) ◽  
pp. 6509-6515 ◽  
Author(s):  
R. T. Okinaka ◽  
K. Cloud ◽  
O. Hampton ◽  
A. R. Hoffmaster ◽  
K. K. Hill ◽  
...  
Keyword(s):  
Bacillus Anthracis ◽  
Regulatory Elements ◽  
Open Reading Frames ◽  
Significant Similarity ◽  
Toxin Genes ◽  
Theta Replication ◽  
Large Plasmids ◽  
High Degree ◽  
Degree Of Similarity ◽  
Reading Frames

ABSTRACT The Bacillus anthracis Sterne plasmid pXO1 was sequenced by random, “shotgun” cloning. A circular sequence of 181,654 bp was generated. One hundred forty-three open reading frames (ORFs) were predicted using GeneMark and GeneMark.hmm, comprising only 61% (110,817 bp) of the pXO1 DNA sequence. The overall guanine-plus-cytosine content of the plasmid is 32.5%. The most recognizable feature of the plasmid is a “pathogenicity island,” defined by a 44.8-kb region that is bordered by inverted IS1627 elements at each end. This region contains the three toxin genes (cya, lef, and pagA), regulatory elements controlling the toxin genes, three germination response genes, and 19 additional ORFs. Nearly 70% of the ORFs on pXO1 do not have significant similarity to sequences available in open databases. Absent from the pXO1 sequence are homologs to genes that are typically required to drive theta replication and to maintain stability of large plasmids in Bacillus spp. Among the ORFs with a high degree of similarity to known sequences are a collection of putative transposases, resolvases, and integrases, suggesting an evolution involving lateral movement of DNA among species. Among the remaining ORFs, there are three sequences that may encode enzymes responsible for the synthesis of a polysaccharide capsule usually associated with serotype-specific virulent streptococci.

scholarly journals Cloning and Characterization of a Gene Cluster Involved in Cyclopentanol Metabolism in Comamonas sp. Strain NCIMB 9872 and Biotransformations Effected by Escherichia coli-Expressed Cyclopentanone 1,2-Monooxygenase

2002 ◽  
Vol 68 (11) ◽  
pp. 5671-5684 ◽  
Author(s):  
Hiroaki Iwaki ◽  
Yoshie Hasegawa ◽  
Shaozhao Wang ◽  
Margaret M. Kayser ◽  
Peter C. K. Lau
Keyword(s):  
Escherichia Coli ◽  
Regulatory Gene ◽  
Regulatory Elements ◽  
Open Reading Frames ◽  
Chromosomal Locus ◽  
New Genes ◽  
Transcriptional Units ◽  
Acid Catalyzed ◽  
Reading Frames

ABSTRACT Cyclopentanone 1,2-monooxygenase, a flavoprotein produced by Pseudomonas sp. strain NCIMB 9872 upon induction by cyclopentanol or cyclopentanone (M. Griffin and P. W. Trudgill, Biochem. J. 129:595-603, 1972), has been utilized as a biocatalyst in Baeyer-Villiger oxidations. To further explore this biocatalytic potential and to discover new genes, we have cloned and sequenced a 16-kb chromosomal locus of strain 9872 that is herein reclassified as belonging to the genus Comamonas. Sequence analysis revealed a cluster of genes and six potential open reading frames designated and grouped in at least four possible transcriptional units as (orf11-orf10-orf9)-(cpnE-cpnD-orf6-cpnC)-(cpnR-cpnB-cpnA)-(orf3-orf4 [partial 3′ end]). The cpnABCDE genes encode enzymes for the five-step conversion of cyclopentanol to glutaric acid catalyzed by cyclopentanol dehydrogenase, cyclopentanone 1,2-monooxygenase, a ring-opening 5-valerolactone hydrolase, 5-hydroxyvalerate dehydrogenase, and 5-oxovalerate dehydrogenase, respectively. Inactivation of cpnB by using a lacZ-Kmr cassette resulted in a strain that was not capable of growth on cyclopentanol or cyclopentanone as a sole carbon and energy source. The presence of σ54-dependent regulatory elements in front of the divergently transcribed cpnB and cpnC genes supports the notion that cpnR is a regulatory gene of the NtrC type. Knowledge of the nucleotide sequence of the cpn genes was used to construct isopropyl-β-thio-d-galactoside-inducible clones of Escherichia coli cells that overproduce the five enzymes of the cpn pathway. The substrate specificities of CpnA and CpnB were studied in particular to evaluate the potential of these enzymes and establish the latter recombinant strain as a bioreagent for Baeyer-Villiger oxidations. Although frequently nonenantioselective, cyclopentanone 1,2-monooxygenase was found to exhibit a broader substrate range than the related cyclohexanone 1,2-monooxygenase from Acinetobacter sp. strain NCIMB 9871. However, in a few cases opposite enantioselectivity was observed between the two biocatalysts.

scholarly journals Genomic and phylogenetic characterization of ChPV2, a novel goat PV closely related to the Xi-PV1 species infecting bovines

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Anouk Willemsen ◽  
Alexander van den Boom ◽  
Julienne Dietz ◽  
Seval Bilge Dagalp ◽  
Firat Dogan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Phylogenetic Analyses ◽  
Regulatory Elements ◽  
Open Reading Frames ◽  
Capra Hircus ◽  
Phylogenetic Position ◽  
Reading Frame ◽  
Phylogenetic Characterization ◽  
Ruminant Species ◽  
Reading Frames

Abstract Background Papillomaviruses (PVs) infecting artiodactyls are very diverse, and only second in number to PVs infecting primates. PVs associated to lesions in economically important ruminant species have been isolated from cattle and sheep. Methods Potential PV DNA from teat lesions of a Damascus goat was isolated, cloned and sequenced. The PV genome was analyzed using bioinformatics approaches to detect open reading frames and to predict potential features of encoded proteins as well as putative regulatory elements. Sequence comparison and phylogenetic analyses using the concatenated E1E2L2L1 nucleotide and amino acid alignments was used to reveal the relationship of the new PV to the known PV diversity and its closest relevants. Results We isolated and characterized the full-genome of novel Capra hircus papillomavirus. We identified the E6, E7, E1, E2, L2, L1 open reading frames with protein coding potential and putative active elements in the ChPV2 proteins and putative regulatory genome elements. Sequence similarities of L1 and phylogenetic analyses using concatenated E1E2L2L1 nucleotide and amino acid alignments suggest the classification as a new PV type designated ChPV2 with a phylogenetic position within the XiPV genus, basal to the XiPV1 species. ChPV2 is not closely related to ChPV1, the other known goat PV isolated from healthy skin, although both of them belong confidently into a clade composed of PVs infecting cervids and bovids. Interestingly, ChPV2 contains an E6 open reading frame whereas all closely related PVs do not Conclusion ChPV2 is a novel goat PV closely related to the Xi-PV1 species infecting bovines. Phylogenetic relationships and genome architecture of ChPV2 and closely related PV types suggest at least two independent E6 losses within the XiPV clade.

scholarly journals Genetic Path of the Emergence of SARS-CoV-2

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Taslima Nasrin ◽  
Safdar Ali
Keyword(s):  
Genetic Basis ◽  
Proteome Analysis ◽  
Open Reading Frames ◽  
Host Cells ◽  
Present Review ◽  
Intermediate Hosts ◽  
Crown Shape ◽  
Reservoir Hosts ◽  
Reading Frames

Context: SARS-CoV-2 is the seventh coronavirus that has humans as the host. Because of its highly infectious nature, toward the end of January 2020, the WHO declared it a public health emergency of international concern. The present review is about understanding the journey of SARS-CoV-2 to its present form with an attempt to assess the genetic basis of its pandemic-causing abilities. Evidence Acquisition: The data for the present review were accessed through different publications and preprint repositories. Results: SARS-CoV-2 is a beta-coronavirus, and is approximately 60 - 140 nm in size. The appearance of its structure as a crown shape under an electron microscope led to the coining of its name ‘Coronavirus’. Comparative genome and proteome analysis exhibits similarities and differences with reference to SARS-CoV. The Open Reading Frames (ORFs) found on the SARS-CoV-2 genome, and their corresponding proteins have been discussed. Bats may act as reservoir hosts but not exclusively. The possibility of snakes as the host, as well as other intermediate hosts, before reaching humans seems plausible. This has been supported by ACE2 receptor diversity and conservation across different tissues and organisms. The role of spike glycoprotein and its interaction with the receptor through specific residues for invading host cells makes a perfect therapeutic target, but the variations therein and the resulting impact on interactions pose challenges for the same. Conclusions: Though the differences between the MERS, SARS-CoV, and SARS-CoV-2 genomes indicate amino acid changes, leading to the present pandemic situation, the fact that new variants are still emerging signifies that the journey is an ongoing one, which requires monitoring.

scholarly journals Characterization of a Novel Phage ΦAb1656-2 and Its Endolysin with Higher Antimicrobial Activity against Multidrug-Resistant Acinetobacter baumannii

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1848
Author(s):  
Kyeongmin Kim ◽  
Md Maidul Islam ◽  
Dooyoung Kim ◽  
Sung Ho Yun ◽  
Jungmin Kim ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Therapeutic Agent ◽  
Catalytic Domain ◽  
Hydrolytic Enzymes ◽  
Multidrug Resistant ◽  
Open Reading Frames ◽  
Nosocomial Pathogen ◽  
Prophage Induction ◽  
Reading Frames

Acinetobacter baumannii is a nosocomial pathogen, which is a problem worldwide due to the emergence of a difficult-to-treat multidrug-resistant A. baumannii (MDRAB). Endolysins are hydrolytic enzymes produced by a bacteriophage that can be used as a potential therapeutic agent for multidrug-resistant bacterial infection in replacing antibiotics. Here, we isolated a novel bacteriophage through prophage induction using mitomycin C from clinical A. baumannii 1656-2. Morphologically, ΦAb1656-2 was identified as a Siphoviridae family bacteriophage, which can infect MDRAB. The whole genome of ΦAb1656-2 was sequenced, and it showed that it is 50.9 kb with a G + C content of 38.6% and 68 putative open reading frames (ORFs). A novel endolysin named AbEndolysin with an N-acetylmuramidase-containing catalytic domain was identified, expressed, and purified from ΦAb1656-2. Recombinant AbEndolysin showed significant antibacterial activity against MDRAB clinical strains without any outer membrane permeabilizer. These results suggest that AbEndolysin could represent a potential antimicrobial agent for treating MDRAB clinical isolates.

scholarly journals Genome of a novel circovirus of starlings, amplified by multiply primed rolling-circle amplification

2006 ◽  
Vol 87 (5) ◽  
pp. 1189-1195 ◽  
Author(s):  
Reimar Johne ◽  
Daniel Fernández-de-Luco ◽  
Ursula Höfle ◽  
Hermann Müller
Keyword(s):  
Rolling Circle Amplification ◽  
Open Reading Frames ◽  
Degenerate Primers ◽  
Rolling Circle ◽  
Specific Pcr ◽  
Sturnus Unicolor ◽  
Evolutionarily Conserved ◽  
Degree Of Similarity ◽  
Reading Frames ◽  
Apparently Healthy

The genus Circovirus comprises small non-enveloped viruses with a circular single-stranded DNA genome. By using PCR with degenerate primers, a novel circovirus (starling circovirus, StCV) was detected in spleen samples of wild starlings (Sturnus vulgaris and Sturnus unicolor) found dead during an epidemic outbreak of septicaemic salmonellosis in northeastern Spain. Using a specific PCR, StCV was also detected in apparently healthy birds from the same population. The genome was amplified using multiply primed rolling-circle amplification and cloned. Open reading frames (ORFs) with similarities to the replication-associated protein and the capsid protein of circoviruses as well as an additional ORF encoding a protein of 106 aa were evident from the sequence. Phylogenetic analysis of circovirus genomes revealed the highest degree of similarity (67·1 %) between StCV and canary circovirus. A similar analysis of the evolutionarily conserved cytochrome b gene of the circovirus host species revealed a strict co-evolution of circoviruses with their hosts; however, the circoviruses showed about a threefold higher genetic divergence than their hosts.

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