Multicellular living organisms and unmodified parts thereof and – Plant – seedling – plant seed – or plant part – per se – Higher plant – seedling – plant seed – or plant part
Reexamination Certificate
1999-10-21
2004-12-14
Ketter, James (Department: 1636)
Multicellular living organisms and unmodified parts thereof and
Plant, seedling, plant seed, or plant part, per se
Higher plant, seedling, plant seed, or plant part
C435S006120, C435S069100, C435S183000, C435S419000, C435S252100, C435S254110, C435S320100, C536S023600
Reexamination Certificate
active
06831207
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from International Application No. PCT/EP98/02483, filed Apr. 27, 1998 and German Application No. 197 17 656.9, filed Apr. 25, 1997. Each of the foregoing applications, patents and publications and all documents cited or referenced therein (“application cited documents”) and all documents cited or referenced in this specification (“herein cited documents”) are hereby incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not applicable.
FIELD OF THE INVENTION
The present invention relates to the subunit CHLD of plant magnesium chelatase (Mg chelatase), to DNA sequences encoding the subunit CHLD of plant Mg chelatase, to processes for preparing the subunit CHLD of plant Mg chelatase, to processes for determining the activity of plant Mg chelatase, and transgenic plants which have been transformed with the Mg chelatase DNA according to the invention.
BACKGROUND OF THE INVENTION
Being photosystem cofactors, chlorophylls play a role in the conversion of light into chemical energy and are thus required for plant growth and survival.
Magnesium is incorporated into porphyrin during chlorophyll biosynthesis with the aid of a membrane—associated enzyme, namely Mg chelatase, which is composed of several subunits.
It has already been disclosed that bacterial Mg chelatase is composed of three subunits (D, H and I), whose corresponding gene sequences are termed bchD, bchH and bchI (Burke et al. (1993), J. Bacteriol. 175, 2414-2422; Coomber et al. (1990), Mol. Microbiol. 4, 977-989; Gibson et al. (1995), Proc. Natl. Acad. Sci. USA, 92, 1941-1844; Jensen et al. (1996), J. Biol. Chem. 271, 16662-16667).
TABLE I
List of the genes of known Mg chelatase subunits
Rhodobacter
Rhodobacter
Synechocys-
Arabidopsis
Antirrhinum
capsulatus
sphaeroides
tis PCC 6803
thaliana
majus
Burke et al.
Coomber et al.
Jensen et al.
Koncz et al.
Hudson et al.
bchD
bchD
chID
bchH
bchH
chIH
chiH
olive
bchl
bchl
chil
ch42
3Dchl
As regards plant Mg chelatases, two subunits have been described to date which seem to correspond to the bacterial Mg chelatase subunits bchH and bchI (Koncz et al., (1990), EMBO J. 9, 1337-1346; Hudson et al., (1993), EMBO J. 12, 3711-3719; Eibson et al., (1996), Plant Physiol. 121, 61-71). It is not known as yet which other subunits participate in the structure of plant Mg chelatase. No enzyme activity was observed with the two known plant subunits CHLI and CHLH, neither alone nor together with the known bacterial subunits of type D (CHLD and BCHD).
Due to their key position in chlorophyll biosynthesis, plant Mg chelatase is a radically new starting point for developing a novel generation of herbicidal compounds with highly specific activity. In addition, the vitality and/or growth of phototrophic uni- and multicellular organisms, in particular bacteria, algae and plants, can be controlled to a high degree by influencing gene expression (suppression, overexpression) of the natural or modified (for example genetically engineered) expression products of Mg chelatase or else by specific Mg chelatase inhibitors.
The enzymatic activity of plant Mg chelatase was originally measured on intact chloroplasts (Castelfranco et al., (1979) Arch. Biochem. Biophys. 192, 592-598; Fuesler et al. (1982) Plant Physiol. 69,421-423). Since then, the activity was also determined on disrupted plastids (Walker et al. (1991) Proc. Natl. Acad. Sci. 88, 5789-5793) and subplastid membrane fractions (Lee, et al. (1992). Plant Physiol. 99,1134-1140).
Surprisingly, there has now been found a DNA which encodes a subunit of the enzyme plant Mg chelatase. The DNA will subsequently be termed chlD, and the amino acid sequence CHLD.
Moreover, it has been found that a subunit CHLD of plant Mg chelatase together with the subunits CHLI and CHLH is, surprisingly, suitable for reconstituting a funtionally intact, i.e. enzymatically active, plant Mg chelatase, so that the plant Mg chelatase subunit CHLD according to the invention provides novel test methods (in vivo and in vitro) for plant Mg chelatase activity.
REFERENCES:
Jensen et al (1996) Mol. Gen. Genet. 250:383-393.*
Papenbrock et al (1997) The Plant Journal 12:981-990.*
Jensen et al (1996) Mol. Gen. Genet. 250:383-393.*
Luo et al , Database GenEMBL, Accession No. AF014399, Oct. 7, 1997.*
Jensen et al (1996) J. Biol. Chem. 271:16662-16667.*
Kannangara et al (1997) Mol. Gen. Genetics (Mar. 18, 1997) 254:85-92.*
Jensen et al., “Structural genes for Mg-chelatase subunits in barley: Xantha-f, -g and -h”, Molecular and General Genetics, vol. 250, pp. 383-394, 1996.
Gibson et al., “A Putative Mg Chelatase Subunit from Arabidopsis thaliana cv C24”, Plant Physiology, vol. 111, pp. 61-71, 1996.
Nakayama et al., “Cloning, Subcellular Localization and Expression of CHLI, A Subunit of Magnesium-Chelatase in Soybean”, Biochemical and Biophysical Research Communications, vol. 215, No. 1, pp. 422-428, 1995.
Kannangara et al., “Magnesium chelatase: association with ribosomes and mutant complementation studies identify barley subunit Xantha-G as a functional counterpart of Rhodobacter subunit BchD”, Molecular and General Genetics, vol. 254, pp. 85-92.
Gibson et al., “Magnesium-protoporphyrin chelatase of Rhodobacter sphaeroides: Reconstitution of activity by combining the products of the bchH, -I, and -D genes expressed inEscherichia coli”, Proceedings of the National Academy of Sciences of the USA, vol. 92, pp. 1941-1944, Mar. 1995.
Hudson et al., “Olive: a key gene required for chlorophyll biosynthesis in Antirrhinum majus”, The EMBO Journal, vol. 12, No. 10, pp. 3711-3719, 1993.
Koncz et al., “Isolation of a gene encoding a novel chloroplast protein by T-DNA tagging in Arabidopsis thaliana”, The EMBO Journal, vol. 9, No. 5, pp. 1337-1346, 1990.
Papenbrock et al. “Mg-chelatase of tobacco: identification of Ch1 D cDNA sequence encoding a third subunit, analysis of the interaction of the three subunits with the yeast two-hybrid system, and reconstitution of the enzyme activity by co-expression of recombinant CHL D, CHL H and CHL 1”, The Plant Journal, vol. 12, No. 5, pp. 981-990, Nov. 1997.
Papenbrock et al. “untitled” EMBL Sequence Data Library, Jan. 1, 1998.
Papenbrock et al. “Identification of a plant Ch1D cDNA sequence homologous to a bacterial gene encoding a third subunit of Mg-chelatase”, EMBL Sequence Data Library, Jul. 1, 1997, Abstract No. XP002076481.
Luo et al., “Cloning and Sequencing of a cDNA Encoding the Putative Mg-Chelatase Subunit D (Accession No. AF014399) from Pea”, Plant Physiology, vol. 115, No. 1 p. 315, Sep. 1997, Abstract No. XP002076482.
Kruse et al., “Isolation and characterisation of tobacco (Nicotiana tabacum) cDNA clones encoding proteins involved in magnesium chelation into protoporphyrin IX”, Plant Molecular Biology, vol. 35, pp. 1053-1056, Dec. 1997.
Gräfe Susanna
Grimm Bernhard
Hänel Frank
Papenbrock Jutta
Schmidt Frank
Frommer & Lawrence & Haug LLP
Hoechst Schering AgrEvo
Ketter James
LandOfFree
DNA sequences encoding for subunit CHLD of plant magnesium... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with DNA sequences encoding for subunit CHLD of plant magnesium..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and DNA sequences encoding for subunit CHLD of plant magnesium... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3299873