Patent granted to Mogen Int. (now Syngenta Mogen B.V.)

The United States patent granted to Syngenta Mogen B.V., is directed to the use of a Cre (c ausing recombination)-recombinase capable of causing site-specific recombination of two separated DNA molecules present in the same Agrobacterium strain. The resulting plasmid is a co-integrated plasmid having a gene of interest and is useful for plant transformation.

The related European patent is similar to the United States patent as both disclose a site-specific recombination system for the generation of a site-specific co-integrated plasmid for plant transformation. In the European patent, however, the recombinase is not limited to Cre recombinase.

Specific Patent Information

Patent Number Title, Independent Claims and Summary of Claims Assignee
US 5635381

  • Earliest priority – 26 February 1992
  • Filed – 20 January 1995
  • Granted – 3 June 1997
  • Expected expiry – 19 January 2015
Title – Agrobacterium bacteria capable of site-specific recombination

Claim 1
An Agrobacterium strain comprising: (i) a structural DNA sequence encoding a site-specific recombinase that is Cre recombinase; and

(ii) a DNA sequence linked thereto which operationally controls expression of said Cre recombinase, said strain further comprising
(iii) a first recombination site.

The patent discloses that a first plasmid bearing a recombination site combines, in a site-specific fashion, with a second plasmid also bearing a recombination site to generate a site-specific co-integrated plasmid. The second plasmid contains a gene of interest linked to a right T-border. The production of the co-integrated plasmid does not require homologous recombination. The Agrobacterium strains used for plant transformation contain the site-specific co-integrated plasmid with the exogenous DNA to plants.

The patent claims an Agrobacterium strain with

  • a DNA sequence encoding Cre recombinase linked to a sequence that controls its expression and
  • a first recombination site (which can be on a plasmid or in the genome).

The claim is a bit ambigious in that it doesn’t state that the recombination site is necessarily recognized by the Cre recombinase, though the specification discloses that an exemplary site is a loxP seqence.

Syngenta Mogen B.V.

EP 628082 B1

  • Earliest priority – 26 February 1992
  • Filed – 25 February 1993
  • Granted – 16 May 2001
  • Expected expiry – 24 February 2013
Title – Agrobacterium strains capable of site-specific recombination

Claim 1
An Agrobacterium strain capable of producing a site-specific recombinase capable of effecting site-specific recombination of a first and second recombination site in said Agrobacterium strain, when present therein, comprising a structural DNA sequence encoding said recombinase and a DNA sequence capable of controlling expression in said Agrobacterium strain.

Designated contracting States at the time of grant are: Austria (patent lapsed as reported by INPADOC), Belgium, Switzerland, Germany, Denmark (patent lapsed as reported by INPADOC), Spain, France, United Kingdom, Greece, Ireland (patent lapsed as reported by INPADOC), Italy, Liechtenstein, Luxembourg, Monaco, Netherlands, Portugal, Sweden (patent lapsed as reported by INPADOC).

Both of Syngenta Mogen’s patents in the United States and in Europe encompass Agrobacterium strains having a plasmid with a gene encoding a recombinase, a sequence to control its expression, vir functions, and a first recombination site.

Unlike the United States patent, the claims of the European patent are broader as the recombinase is not limited to a Cre recombinase. Other site-specific recombinases may be encompassed by the European patent claims.  The European patent does explicitly claim that the recombinase can mediate recombination between the first recombination site and a second recombination site but claim 1 does not require that the first or second site be on a plasmid.

Note: Patent information on this page was last updated on 1 March 2006.