scholarly journals Additional conjugation systems for inter-domain plasmid transfer to the diatom Phaeodactylum tricornutum

2017 ◽  
Author(s):  
Anthony K. Kang ◽  
Vincent A Bielinski ◽  
Tayah M. Bolt ◽  
Christopher L Dupont ◽  
Philip D Weyman
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Dna Transfer ◽  
Type Iv Secretion System ◽  
Chromosomal Integration ◽  
E Coli ◽  
Type Iv ◽  
Conjugative Gene Transfer ◽  
Conjugation Process

Bacterial conjugation utilizes a type IV secretion system and a DNA transfer mechanism to deliver DNA from one cell to another. Conjugative partners are conventionally confined to the prokaryotic domain. In a prominent exception, Agrobacterium tumefaciens type IV secretion-mediated transfer of DNA to plant cells can result in subsequent chromosomal integration. Recently, we demonstrated interdomain conjugation from Escherichia coli to the diatom Phaeodactylum tricornutum with the subsequent maintenance of an episome at chromosomal copy numbers if it contains diatom centromeres or centromere-like elements. The genes involved in the conjugation process can be separated into those encoding the type IV secretion system, also called the mating pair formation (MPF) genes, and genes involved in DNA processing called the mobilization (MOB) genes. Various protein families compose each class of conjugation genes, including common MOB types F, P, and Q and MPF types F, P, and T. The conjugative transfer from E. coli to P. tricornutum was demonstrated with a vector expressing MOBP and MTFP. Here we show that the MOBPsystem can be deleted and complemented with a MOBQ system in E.coli-diatom conjugations with subsequent episomal maintenaince. Utilization of both MOBP and MOBQ systems results in substantially higher efficiencies in E. coli-diatom conjugation. Finally, we demonstrate conjugative gene transfer between P. tricornutum and A. tumefaciens expressing a MPFT, the first demonstration of this system in diatoms,resulting in episomal maintainance or chromosomal integration, depending on the ex-conjugant. The promiscuity of MOB and MTF systems permitting prokaryote to diatom conjugative DNA transfer suggest major environmental and evolutionary importance of this process. The increased efficiency of dual MOB systems immediately improves genetic engineering in diatoms and has interesting basic cellular biology implications.

scholarly journals Additional conjugation systems for inter-domain plasmid transfer to the diatom Phaeodactylum tricornutum

2017 ◽  
Author(s):  
Anthony K. Kang ◽  
Vincent A Bielinski ◽  
Tayah M. Bolt ◽  
Christopher L Dupont ◽  
Philip D Weyman
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Dna Transfer ◽  
Type Iv Secretion System ◽  
Chromosomal Integration ◽  
E Coli ◽  
Type Iv ◽  
Conjugative Gene Transfer ◽  
Conjugation Process

Bacterial conjugation utilizes a type IV secretion system and a DNA transfer mechanism to deliver DNA from one cell to another. Conjugative partners are conventionally confined to the prokaryotic domain. In a prominent exception, Agrobacterium tumefaciens type IV secretion-mediated transfer of DNA to plant cells can result in subsequent chromosomal integration. Recently, we demonstrated interdomain conjugation from Escherichia coli to the diatom Phaeodactylum tricornutum with the subsequent maintenance of an episome at chromosomal copy numbers if it contains diatom centromeres or centromere-like elements. The genes involved in the conjugation process can be separated into those encoding the type IV secretion system, also called the mating pair formation (MPF) genes, and genes involved in DNA processing called the mobilization (MOB) genes. Various protein families compose each class of conjugation genes, including common MOB types F, P, and Q and MPF types F, P, and T. The conjugative transfer from E. coli to P. tricornutum was demonstrated with a vector expressing MOBP and MTFP. Here we show that the MOBPsystem can be deleted and complemented with a MOBQ system in E.coli-diatom conjugations with subsequent episomal maintenaince. Utilization of both MOBP and MOBQ systems results in substantially higher efficiencies in E. coli-diatom conjugation. Finally, we demonstrate conjugative gene transfer between P. tricornutum and A. tumefaciens expressing a MPFT, the first demonstration of this system in diatoms,resulting in episomal maintainance or chromosomal integration, depending on the ex-conjugant. The promiscuity of MOB and MTF systems permitting prokaryote to diatom conjugative DNA transfer suggest major environmental and evolutionary importance of this process. The increased efficiency of dual MOB systems immediately improves genetic engineering in diatoms and has interesting basic cellular biology implications.

Investigation of the Directionality and Kinetics of DNA Transfer by a Bacterial Type IV Secretion System

2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Olukemi P. Akinleye ◽  
Betelhem B. Gemechu ◽  
Sabrina Ali ◽  
Melanie B. Berkmen
Keyword(s):  
Secretion System ◽  
Type Iv Secretion ◽  
Dna Transfer ◽  
Type Iv Secretion System ◽  
Type Iv ◽  
Kinetics Of ◽  
Bacterial Type

scholarly journals High-throughput fitness screening and transcriptomics identify a role for a type IV secretion system in the pathogenesis of Crohn’s disease-associated Escherichia coli

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wael Elhenawy ◽  
Sarah Hordienko ◽  
Steven Gould ◽  
Alexander M. Oberc ◽  
Caressa N. Tsai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Type Iv Secretion System ◽  
E Coli ◽  
Type Iv ◽  
Gut Colonization

AbstractAdherent-invasive Escherichia coli (AIEC) are pathogenic bacteria frequently isolated from patients who have Crohn’s disease (CD). Despite the phenotypic differences between AIEC and commensal E. coli, comparative genomic approaches have been unable to differentiate these two groups, making the identification of key virulence factors a challenge. Here, we conduct a high-resolution, in vivo genetic screen to map AIEC genes required for intestinal colonization of mice. In addition, we use in vivo RNA-sequencing to define the host-associated AIEC transcriptome. We identify diverse metabolic pathways required for efficient gut colonization by AIEC and show that a type IV secretion system (T4SS) is required to form biofilms on the surface of epithelial cells, thereby promoting AIEC persistence in the gut. E. coli isolated from CD patients are enriched for a T4SS, suggesting a possible connection to disease activity. Our findings establish the T4SS as a principal AIEC colonization factor and highlight the use of genome-wide screens in decoding the infection biology of CD-associated bacteria that otherwise lack a defined genetic signature.

scholarly journals A New Type IV Secretion System Promotes Conjugal Transfer in Agrobacterium tumefaciens

2002 ◽  
Vol 184 (17) ◽  
pp. 4838-4845 ◽  
Author(s):  
Lishan Chen ◽  
Yuching Chen ◽  
Derek W. Wood ◽  
Eugene W. Nester
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Bartonella Henselae ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Ti Plasmid ◽  
Dna Transfer ◽  
Conjugal Transfer ◽  
Type Iv Secretion System ◽  
Plant Host ◽  
Type Iv

ABSTRACT Two DNA transfer systems encoded by the tumor-inducing (Ti) plasmid have been previously identified in Agrobacterium tumefaciens. The virB operon is required for the transfer of transferred DNA to the plant host, and the trb system encodes functions required for the conjugal transfer of the Ti plasmid between cells of Agrobacterium. Recent availability of the genome sequence of Agrobacterium allowed us to identify a third system that is most similar to the VirB type IV secretion system of Bartonella henselae. We have designated this system avhB for Agrobacterium virulence homologue virB. The avhB loci reside on pAtC58 and encode at least 10 proteins (AvhB2 through AvhB11), 7 of which display significant similarity to the corresponding virulence-associated VirB proteins of the Ti plasmid. However, the AvhB system is not required for tumor formation; rather, it mediates the conjugal transfer of the pAtC58 cryptic plasmid between cells of Agrobacterium. This transfer occurs in the absence of the Ti plasmid-encoded VirB and Trb systems. Like the VirB system, AvhB products promote the conjugal transfer of the IncQ plasmid RSF1010, suggesting that these products comprise a mating-pair formation system. The presence of plasmid TiC58 or plasmid RSF1010 reduces the conjugal transfer efficiency of pAtC58 10- or 1,000-fold, respectively. These data suggest that complex substrate interactions exist among the three DNA transfer systems of Agrobacterium.

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