Faculty Opinions recommendation of Agrobacterium-mediated T-DNA transfer and integration by minimal VirD2 consisting of the relaxase domain and a type IV secretion system translocation signal.

Author(s):  
Vitaly Citovsky ◽  
Benoît Lacroix
2017 ◽  
Author(s):  
Anthony K. Kang ◽  
Vincent A Bielinski ◽  
Tayah M. Bolt ◽  
Christopher L Dupont ◽  
Philip D Weyman

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.


2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Olukemi P. Akinleye ◽  
Betelhem B. Gemechu ◽  
Sabrina Ali ◽  
Melanie B. Berkmen

2017 ◽  
Author(s):  
Anthony K. Kang ◽  
Vincent A Bielinski ◽  
Tayah M. Bolt ◽  
Christopher L Dupont ◽  
Philip D Weyman

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.


2002 ◽  
Vol 184 (17) ◽  
pp. 4838-4845 ◽  
Author(s):  
Lishan Chen ◽  
Yuching Chen ◽  
Derek W. Wood ◽  
Eugene W. Nester

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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