scholarly journals Complete Genome Sequence of the Naegleria fowleri (Strain LEE) Closed Circular Extrachromosomal Ribosomal DNA Element

2020 ◽  
Vol 9 (49) ◽  
Author(s):  
John C. Mullican ◽  
Kristen M. Drescher ◽  
Nora M. Chapman ◽  
Steven Tracy

ABSTRACT The circular extrachromosomal ribosomal DNA (rDNA) element of Naegleria fowleri strain LEE was molecularly cloned and fully sequenced. The element comprises 15,786 bp and contains a single copy of the organism’s rDNA cistron. The nonribosomal sequence contains five potential open reading frames, two large direct repeat sequences, and numerous smaller repeated-sequence regions.

2015 ◽  
Vol 59 (8) ◽  
pp. 4577-4583 ◽  
Author(s):  
Elena Gómez-Sanz ◽  
Sybille Schwendener ◽  
Andreas Thomann ◽  
Stefanie Gobeli Brawand ◽  
Vincent Perreten

ABSTRACTA methicillin-resistantmecB-positiveMacrococcus caseolyticus(strain KM45013) was isolated from the nares of a dog with rhinitis. It contained a novel 39-kb transposon-defective completemecB-carrying staphylococcal cassette chromosomemecelement (SCCmecKM45013). SCCmecKM45013contained 49 coding sequences (CDSs), was integrated at the 3′ end of the chromosomalorfXgene, and was delimited at both ends by imperfect direct repeats functioning as integration site sequences (ISSs). SCCmecKM45013presented two discontinuous regions of homology (SCCmeccoverage of 35%) to the chromosomal and transposon Tn6045-associated SCCmec-like element ofM. caseolyticusJCSC7096: (i) themecgene complex (98.8% identity) and (ii) theccr-carrying segment (91.8% identity). Themecgene complex, located at the right junction of the cassette, also carried the β-lactamase geneblaZm(mecRm-mecIm-mecB-blaZm). SCCmecKM45013contained two cassette chromosome recombinase genes,ccrAm2andccrBm2, which shared 94.3% and 96.6% DNA identity with those of the SCCmec-like element of JCSC7096 but shared less than 52% DNA identity with the staphylococcalccrABandccrCgenes. Three distinct extrachromosomal circularized elements (the entire SCCmecKM45013, ΨSCCmecKM45013lacking theccrgenes, and SCCKM45013lackingmecB) flanked by one ISS copy, as well as the chromosomal regions remaining after excision, were detected. An unconventional circularized structure carrying themecBgene complex was associated with two extensive direct repeat regions, which enclosed two open reading frames (ORFs) (ORF46 and ORF51) flanking the chromosomalmecB-carrying gene complex. This study revealedM. caseolyticusas a potential disease-associated bacterium in dogs and also unveiled an SCCmecelement carryingmecBnot associated with Tn6045in the genusMacrococcus.


2007 ◽  
Vol 24 (12) ◽  
pp. 2648-2656 ◽  
Author(s):  
Akira Hikosaka ◽  
Toshihiro Kobayashi ◽  
Yumiko Saito ◽  
Akira Kawahara

Abstract A new family, termed TxpB, of DNA transposons belonging to the piggyBac superfamily was found in 3 Xenopus species (Xenopus tropicalis, Xenopus laevis, and Xenopus borealis). Two TxpB subfamilies of Kobuta and Uribo1 were found in all the 3 species, and another subfamily termed Uribo2 was found in X. tropicalis. Molecular phylogenetic analyses of their open reading frames (ORFs) revealed that TxpB transposons have been maintained for over 100 Myr. Both the Uribo1 and the Uribo2 ORFs were present as multiple copies in each genome, and some of them were framed by terminal inverted repeat sequences. In contrast, all the Kobuta ORFs were present as a single copy in each genome and exhibited high evolutionary conservation, suggesting domestication of Kobuta genes by the host. Genomic insertion polymorphisms of the Uribo1 and Uribo2 transposons (nonautonomous type) were observed in a single species of X. tropicalis, indicating recent transposition events. Transfection experiments in cell culture revealed that an expression vector construct for the intact Uribo2 ORF caused precise excision of a nonautonomous Uribo2 element from the target vector construct but that for the Kobuta ORF did not. The present results support our viewpoint that some Uribo2 members are naturally active autonomous transposons, whereas Kobuta members may be domesticated by hosts.


2001 ◽  
Vol 67 (8) ◽  
pp. 3564-3576 ◽  
Author(s):  
Chitladda Mahanivong ◽  
John D. Boyce ◽  
Barrie E. Davidson ◽  
Alan J. Hillier

ABSTRACT The Lactococcus lactis temperate bacteriophage BK5-T is one of twelve type phages that define L. lactis phage species. This paper describes the nucleotide sequence and analysis of a 21-kbp region of the BK5-T genome and completes the nucleotide sequence of the genome of this phage. The 40,003-nucleotide linear genome encodes 63 open reading frames. Sequence runoff experiments showed that the cohesive ends of the BK5-T genome contained a 12-bp 3′ single-stranded overhang with the sequence 5′-CACACACATAGG-3′. Two major BK5-T structural proteins, of approximately 30 and 20 kDa, were identified, and N-terminal sequence analysis determined that they were encoded by orf7 and orf12, respectively. A 169-bp fragment containing a 37-bp direct repeat and several smaller repeat sequences conferred resistance to BK5-T infection when introduced in trans to the host cell and is likely a part of the BK5-T origin of replication (ori).


2018 ◽  
Vol 6 (6) ◽  
pp. e00020-18 ◽  
Author(s):  
John C. Mullican ◽  
Nora M. Chapman ◽  
Steven Tracy

ABSTRACT The circular extrachromosomal element of Naegleria gruberi strain EGB was linearized, molecularly cloned, and fully sequenced. The sequence comprises 14,007 bp and encodes the organism’s rRNA genes, two potential open reading frames, and numerous repeated sequence regions.


2016 ◽  
Vol 198 (9) ◽  
pp. 1393-1400 ◽  
Author(s):  
Guangyu E. Chen ◽  
Andrew Hitchcock ◽  
Philip J. Jackson ◽  
Roy R. Chaudhuri ◽  
Mark J. Dickman ◽  
...  

ABSTRACTThe major photopigment of the cyanobacteriumAcaryochloris marinais chlorophylld, while its direct biosynthetic precursor, chlorophylla, is also present in the cell. These pigments, along with the majority of chlorophylls utilized by oxygenic phototrophs, carry an ethyl group at the C-8 position of the molecule, having undergone reduction of a vinyl group during biosynthesis. Two unrelated classes of 8-vinyl reductase involved in the biosynthesis of chlorophylls are known to exist, BciA and BciB. The genome ofAcaryochloris marinacontains open reading frames (ORFs) encoding proteins displaying high sequence similarity to BciA or BciB, although they are annotated as genes involved in transcriptional control (nmrA) and methanogenesis (frhB), respectively. These genes were introduced into an 8-vinyl chlorophylla-producing ΔbciBstrain ofSynechocystissp. strain PCC 6803, and both were shown to restore synthesis of the pigment with an ethyl group at C-8, demonstrating their activities as 8-vinyl reductases. We propose thatnmrAandfrhBbe reassigned asbciAandbciB, respectively; transcript and proteomic analysis ofAcaryochloris marinareveal that bothbciAandbciBare expressed and their encoded proteins are present in the cell, possibly in order to ensure that all synthesized chlorophyll pigment carries an ethyl group at C-8. Potential reasons for the presence of two 8-vinyl reductases in this strain, which is unique for cyanobacteria, are discussed.IMPORTANCEThe cyanobacteriumAcaryochloris marinais the best-studied phototrophic organism that uses chlorophylldfor photosynthesis. Unique among cyanobacteria sequenced to date, its genome contains ORFs encoding two unrelated enzymes that catalyze the reduction of the C-8 vinyl group of a precursor molecule to an ethyl group. Carrying a reduced C-8 group may be of particular importance to organisms containing chlorophylld. Plant genomes also contain orthologs of both of these genes; thus, the bacterial progenitor of the chloroplast may also have contained bothbciAandbciB.


2011 ◽  
Vol 77 (10) ◽  
pp. 3443-3450 ◽  
Author(s):  
Evelien M. Adriaenssens ◽  
Pieter-Jan Ceyssens ◽  
Vincent Dunon ◽  
Hans-Wolfgang Ackermann ◽  
Johan Van Vaerenbergh ◽  
...  

ABSTRACTPantoea agglomeransis a common soil bacterium used in the biocontrol of fungi and bacteria but is also an opportunistic human pathogen. It has been described extensively in this context, but knowledge of bacteriophages infecting this species is limited. Bacteriophages LIMEzero and LIMElight ofP. agglomeransare lytic phages, isolated from soil samples, belonging to thePodoviridaeand are the firstPantoeaphages of this family to be described. The double-stranded DNA (dsDNA) genomes (43,032 bp and 44,546 bp, respectively) encode 57 and 55 open reading frames (ORFs). Based on the presence of an RNA polymerase in their genomes and their overall genome architecture, these phages should be classified in the subfamily of theAutographivirinae, within the genus of the “phiKMV-like viruses.” Phylogenetic analysis of all the sequenced members of theAutographivirinaesupports the classification of phages LIMElight and LIMEzero as members of the “phiKMV-like viruses” and corroborates the subdivision into the different genera. These data expand the knowledge ofPantoeaphages and illustrate the wide host diversity of phages within the “phiKMV-like viruses.”


2012 ◽  
Vol 78 (24) ◽  
pp. 8719-8734 ◽  
Author(s):  
Mariángeles Briggiler Marcó ◽  
Josiane E. Garneau ◽  
Denise Tremblay ◽  
Andrea Quiberoni ◽  
Sylvain Moineau

ABSTRACTWe characterized twoLactobacillus plantarumvirulent siphophages, ATCC 8014-B1 (B1) and ATCC 8014-B2 (B2), previously isolated from corn silage and anaerobic sewage sludge, respectively. Phage B2 infected two of the eightL. plantarumstrains tested, while phage B1 infected three. Phage adsorption was highly variable depending on the strain used. Phage defense systems were found in at least twoL. plantarumstrains, LMG9211 and WCSF1. The linear double-stranded DNA genome of thepac-type phage B1 had 38,002 bp, a G+C content of 47.6%, and 60 open reading frames (ORFs). Surprisingly, the phage B1 genome has 97% identity with that ofPediococcus damnosusphage clP1 and 77% identity with that ofL. plantarumphage JL-1; these phages were isolated from sewage and cucumber fermentation, respectively. The double-stranded DNA (dsDNA) genome of thecos-type phage B2 had 80,618 bp, a G+C content of 36.9%, and 127 ORFs with similarities to those ofBacillusandLactobacillusstrains as well as phages. Some phage B2 genes were similar to ORFs fromL. plantarumphage LP65 of theMyoviridaefamily. Additionally, 6 tRNAs were found in the phage B2 genome. Protein analysis revealed 13 (phage B1) and 9 (phage B2) structural proteins. To our knowledge, this is the first report describing such high identity between phage genomes infecting different genera of lactic acid bacteria.


2004 ◽  
Vol 78 (8) ◽  
pp. 4370-4375 ◽  
Author(s):  
Alfred L. Roca ◽  
Jill Pecon-Slattery ◽  
Stephen J. O'Brien

ABSTRACT We isolated and sequenced two complete endogenous feline leukemia viruses (enFeLVs), designated enFeLV-AGTT and enFeLV-GGAG. In enFeLV-AGTT, the open reading frames are reminiscent of a functioning FeLV genome, and the 5′ and 3′ long terminal repeat sequences are identical. Neither endogenous provirus is genetically fixed in cats but polymorphic, with 8.9 and 15.2% prevalence for enFeLV-AGTT and enFeLV-GGAG, respectively, among a survey of domestic cats. Neither provirus was found in the genomes of related species of the Felis genus, previously shown to harbor enFeLVs. The absence of mutational divergence, polymorphic incidence in cats, and absence in related species suggest that these enFeLVs may have entered the germ line more recently than previously believed, perhaps coincident with domestication, and reopens the question of whether some enFeLVs might be replication competent.


2020 ◽  
Vol 9 (25) ◽  
Author(s):  
Wesley D. Rhinehart ◽  
Amanda J. Laidlaw ◽  
Alexis M. O’Neal ◽  
Jessica A. Toller ◽  
Miriam Segura-Totten ◽  
...  

ABSTRACT Novel mycobacteriophage XianYue was isolated in Northeast Georgia and infects Mycobacteria smegmatis mc2155. Actinobacteriophages which share at least 50% nucleotide identity are grouped into clusters, with XianYue in cluster A2. Its genome is 52,907 bp with 91 open reading frames (ORFs) and 62.9% GC content, and it shares 86.51% nucleotide identity with mycobacteriophage Trixie.


2019 ◽  
Vol 8 (32) ◽  
Author(s):  
Yen-Te Liao ◽  
Yujie Zhang ◽  
Alexandra Salvador ◽  
Vivian C. H. Wu

Escherichia phage vB_EcoM-Sa45lw, a new member of the T4-like phages, was isolated from surface water in a produce-growing area. The phage, containing double-stranded DNA with a genome size of 167,353 bp and 282 predicted open reading frames (ORFs), is able to infect generic Escherichia coli and Shiga toxin-producing E. coli O45 and O157 strains.


Sign in / Sign up

Export Citation Format

Share Document