Faculty Opinions recommendation of Characterization of the integration and modular excision of the integrative conjugative element PAISt in Streptomyces turgidiscabies Car8.

ABSTRACT A novel type II restriction and modification (R-M) system,Sth368I, which confers resistance to φST84, was found inStreptococcus thermophilus CNRZ368 but not in the very closely related strain A054. Partial sequencing of the integrative conjugative element ICESt1, carried by S. thermophilus CNRZ368 but not by A054, revealed a divergent cluster of two genes, sth368IR and sth368IM. The protein sequence encoded by sth368IR is related to the type II endonucleases R.LlaKR2I and R.Sau3AI, which recognize and cleave the sequence 5′-GATC-3′. The protein sequence encoded by sth368IM is very similar to numerous type II 5-methylcytosine methyltransferases, including M.LlaKR2I and M.Sau3AI. Cell extracts of CNRZ368 but not A054 were found to cleave at the GATC site. Furthermore, the C residue of the sequence 5′-GATC-3′ was found to be methylated in CNRZ368 but not in A054. Cloning and integration of a copy of sth368IR and sth368IMin the A054 chromosome confers on this strain phenotypes similar to those of CNRZ368, i.e., phage resistance, endonuclease activity of cell extracts, and methylation of the sequence 5′-GATC-3′. Disruption of sth368IR removes resistance and restriction activity. We conclude that ICESt1 encodes an R-M system, Sth368I, which recognizes the sequence 5′-GATC-3′ and is related to the Sau3AI and LlaKR2I restriction systems.

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The biochemical characterization of three imine-reducing enzymes from Streptosporangium roseum DSM43021, Streptomyces turgidiscabies and Paenibacillus elgii

Applied Microbiology and Biotechnology ◽

10.1007/s00253-016-7740-0 ◽

2016 ◽

Vol 100 (24) ◽

pp. 10509-10520 ◽

Cited By ~ 12

Author(s):

Philipp N. Scheller ◽

Bettina M. Nestl

Keyword(s):

Biochemical Characterization ◽

Streptomyces Turgidiscabies

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Characterization of TMexCD3-TOprJ3, an RND-type efflux system conferring resistance to tigecycline in Proteus mirabilis, and its associated Integrative Conjugative Element

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02712-20 ◽

2021 ◽

Author(s):

Qian Wang ◽

Kai Peng ◽

Yuan Liu ◽

Xia Xiao ◽

Zhiqiang Wang ◽

...

Keyword(s):

Proteus Mirabilis ◽

Efflux Pump ◽

Current Knowledge ◽

Gene Clusters ◽

The Novel ◽

Genomic Epidemiology ◽

Integrative Conjugative Element ◽

Antimicrobial Resistance Genes ◽

Rnd Efflux Pump

The emergence and transmission of novel antimicrobial resistance genes pose a great threat to public health globally. Recently, the plasmid-encoding RND efflux pump TMexCD1-TOprJ1 in Klebsiella pneumoniae was reported to reduce the sensitivity of multiple antimicrobials. Herein, we identified a pandrug-resistant Proteus mirabilis isolate, which harbored the novel tmexCD3-toprJ3 gene cluster located on SXT/R391 ICE. This study expands current knowledge in transfer mechanism of tmexCD1-toprJ1-like gene clusters among P. mirabilis and warrant further genomic epidemiology investigations.

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Characterization of a Novel Integrative Element, ICESt1, in the Lactic Acid BacteriumStreptococcus thermophilus

Applied and Environmental Microbiology ◽

10.1128/aem.66.4.1749-1753.2000 ◽

2000 ◽

Vol 66 (4) ◽

pp. 1749-1753 ◽

Cited By ~ 27

Author(s):

Vincent Burrus ◽

Yvonne Roussel ◽

Bernard Decaris ◽

Gérard Guédon

Keyword(s):

Lactic Acid ◽

Streptococcus Thermophilus ◽

Conjugative Transfer ◽

Gene Encoding ◽

Conjugative Transposon ◽

Site Specific ◽

Conjugative Transposons ◽

Integrative Conjugative Element ◽

A Site

ABSTRACT The 35.5-kb ICESt1 element of Streptococcus thermophilus CNRZ368 is bordered by a 27-bp repeat and integrated into the 3′ end of a gene encoding a putative fructose-1,6-biphosphate aldolase. This element encodes site-specific integrase and excisionase enzymes related to those of conjugative transposons Tn5276and Tn5252. The integrase was found to be involved in a site-specific excision of a circular form. ICESt1 also encodes putative conjugative transfer proteins related to those of the conjugative transposon Tn916. Therefore, ICESt1could be or could be derived from an integrative conjugative element.

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Chromosomal integration of Tn5253 occurs downstream of a conserved 11-bp sequence of the rbgA gene in Streptococcus pneumoniae and in all the other known hosts of this integrative conjugative element (ICE)

Mobile DNA ◽

10.1186/s13100-021-00253-z ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Francesco Santoro ◽

Valeria Fox ◽

Alessandra Romeo ◽

Elisa Lazzeri ◽

Gianni Pozzi ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Integration Site ◽

Bacterial Species ◽

Functional Characterization ◽

Chromosomal Integration ◽

Bacterial Genomes ◽

Microbial Genomes ◽

The Core ◽

Integrative Conjugative Element

Abstract Background Tn5253, a composite Integrative Conjugative Element (ICE) of Streptococcus pneumoniae carrying tet(M) and cat resistance determinants, was found to (i) integrate at specific 83-bp integration site (attB), (ii) produce circular forms joined by a 84-bp sequence (attTn), and (iii) restore the chromosomal integration site. The purpose of this study is to functionally characterize the attB in S. pneumoniae strains with different genetic backgrounds and in other bacterial species, and to investigate the presence of Tn5253 attB site into bacterial genomes. Results Analysis of representative Tn5253-carryng transconjugants obtained in S. pneumoniae strains with different genetic backgrounds and in other bacterial species, namely Streptococcus agalactiae, Streptococcus gordonii, Streptococcus pyogenes, and Enterococcus faecalis showed that: (i) Tn5253 integrates in rbgA of S. pneumoniae and in orthologous rbgA genes of other bacterial species, (ii) integration occurs always downstream of a 11-bp sequence conserved among streptococcal and enterococcal hosts, (iii) length of the attB site corresponds to length of the duplication after Tn5253 integration, (iv) attB duplication restores rbgA CDS, (v) Tn5253 produced circular forms containing the attTn site at a concentration ranging between 2.0 × 10−5 to 1.2 × 10−2 copies per chromosome depending on bacterial species and strain, (vi) reconstitution of attB sites occurred at 3.7 × 10−5 to 1.7 × 10−2 copies per chromosome. A database search of complete microbial genomes using Tn5253 attB as a probe showed that (i) thirteen attB variants were present in the 85 complete pneumococcal genomes, (ii) in 75 pneumococcal genomes (88.3 %), the attB site was 83 or 84 nucleotides in length, while in 10 (11.7 %) it was 41 nucleotides, (iii) in other 19 bacterial species attB was located in orthologous rbgA genes and its size ranged between 17 and 84 nucleotides, (iv) the 11-bp sequence, which correspond to the last 11 nucleotides of attB sites, is conserved among the different bacterial species and can be considered the core of the Tn5253 integration site. Conclusions A functional characterization of the Tn5253 attB integration site combined with genome analysis contributed to elucidating the potential of Tn5253 horizontal gene transfer among different bacterial species.

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Morphological Characterization of Mycobacteriophage R1

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051281 ◽

1974 ◽

Vol 32 ◽

pp. 254-255

Author(s):

B. L. Soloff ◽

T. A. Rado

Keyword(s):

Carbon Source ◽

Stationary Phase ◽

Growth Phase ◽

Minimal Medium ◽

Morphological Characterization ◽

Logarithmic Growth Phase ◽

Complete Lysis ◽

Lysogenic Culture ◽

Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

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AEM analysis of crystallization in Ti-based amorphous alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075142 ◽

1983 ◽

Vol 41 ◽

pp. 270-271

Author(s):

A.R. Pelton ◽

A.F. Marshall ◽

Y.S. Lee

Keyword(s):

Magnetic Properties ◽

Amorphous Alloys ◽

Amorphous Materials ◽

Isothermal Annealing ◽

Amorphous Matrix ◽

Nucleation And Growth ◽

Current Interest ◽

Amorphous Films ◽

Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

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