English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Virulence proteins VirD1 and VirD2 are subunits of a relaxosome-like protein complex that mediates conjugational transfer of a Ti plasmid segment, the T-DNA, from Agrobacterium into higher plants. The VirD1-VirD2 complex binds to 25-bp repeats at the borders of the T-DNA and catalyzes sequence-specific nicking of the conjugative DNA strand (the T-strand) at the third base of these repeats. Nuclear localization signals present in VirD2 target the T-strand to plant cell nuclei. In addition, VirD2 probably plays a role in the high-frequency integration of the T-DNA into the plant genome by illegitimate recombination. Whereas Agrobacterium transformation of dicots is very efficient, T-DNA integration in most monocots can barely be detected. To develop an artificial T-DNA delivery system for monocots, a technique for efficient in vitro production of T-strand DNAs was established by using VirD1 and VirD2 proteins purified from overexpressing Escherichia coli strains. The topoisomerase-like VirD2 enzyme was shown to mediate precise, sequence-specific cleavage of T-DNA border sequences carried by single-stranded DNA templates, even in the absence of VirD1 protein. During this reaction, VirD2 remains covalently bound to the 5' end of artificial T-strand DNAs. In contrast, VirD2, alone or in complex with VirD1, fails to nick linear double-stranded DNA templates in vitro.

Agrobacterium T-strand production in vitro: sequence-specific cleavage and 5' protection of single-stranded DNA templates by purified VirD2 protein.