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
2001-10-30
2004-09-14
Bui, Phuong T. (Department: 1638)
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
C800S278000, C536S023100, C536S023200, C536S023600, C435S193000, C435S320100, C435S419000
Reexamination Certificate
active
06791015
ABSTRACT:
FIELD OF THE INVENTION
This invention is in the field of plant molecular biology. More specifically, this invention pertains to nucleic acid fragments encoding fructosyltransferases in plants and seeds.
BACKGROUND OF THE INVENTION
Fructans are linear or branched polymers of repeating fructose residues with usually one terminal glucose unit. The number of residues contained in an individual polymer, also known as the degree of polymerization (DP), varies greatly depending on the source from which the polymer is isolated. Several bacteria can produce fructans with a DP 5000 or greater, while low DP fructans (DP 3 to 200) are found in over 40,000 plant species.
Based on their structure, several types of fructans can be identified in higher plants. The most characterized plant fructan is inulin. Inulin contains linear &bgr;(2-1)-linked fructosyl residues and commonly occurs in the Asterales such as Jerusalem artichoke (
Helianthus tuberosus
), sunflower (Helianthus sp.), Belgian endive (
Cichorium intybus
) and artichoke (
Cynara scolymus
). Inulin synthesis is initiated by sucrose:sucrose 1-fructosyltransferase (1-SST; EC 2.4.1.99) which catalyses the conversion of sucrose into isokestose (also named 1-kestose) and glucose. Additional fructosyl units are added onto isokestose, by the action of a fructan:fructan 1-fructosyltransferase (1-FFT, EC 2.4.1.100) resulting in a &bgr;(2-1)-linked fructose oligomer.
A second type of fructan is called levan and consists of linear &bgr;(2-6) linked fructosyl residues. Grasses such as
Dactylis glomerata
and
Phleum pratense
contain levans with a DP up to 200. Levans are synthesized by a sucrose:fructan 6-fructosyltransferase (6-SFT; EC 2.4.1.10) that uses sucrose as a fructosyl donor and acceptor to produce 6-kestose. Polymerization of 6-kestose is believed to be catalyzed by 6-SFT as well, using sucrose as the fructosyl donor.
A third type of fructan, graminan (also called mixed-levan), is found in many Poales such as barley and wheat. These plants use an SST to produce iso-kestose from sucrose, and 6-SFT to further polymerize isokestose, resulting in a fructan containing both the &bgr;(2-1) and the &bgr;(2-6) linked fructosyl residues.
The fourth type of fructan is often referred to as the neo-kestose series of fructans. The neo-kestose series have fructosyl residues on the carbon 1 and 6 of glucose producing a polymer with fructosyl residues on either end of the sucrose molecule. The inulin-neoseries found in Liliales such as onion (
Allium cepa
), leek (
Allium porrum
), and asparagus (
Asparagus officinales
) contain mainly a &bgr;(2-1)-linked fructose polymer linked to carbon 1 and 6 of glucose, while the levan-neoseries contain mainly a &bgr;(2-6)-linked fructose polymer linked to carbon 1 and 6 of glucose. Neoseries fructans are believed to be synthesized by the concerted action of 1-SST (producing isokestose) and 6G-FFT, a specific fructan:fructan 6G-fructosyltransferase that polymerizes fructosyl units onto carbon 6 of glucose.
Industrial applications of fructans are very diverse and range from medical, food, and feed applications, as well as the use of fructans as a raw material for the production of industrial polymers and high-fructose syrup. Regardless of size, fructose polymers are not metabolized by humans and animals. Fructans can enhance animal health and performance by being selectively fermented by beneficial organisms such as Bifidibacterium in the large intestine of animals, at the expense of pathogenic organisms such as
E coli
and Salmonella, leading to altered fatty acid profiles, increased nutrient absorption, and decreased levels of blood cholesterol. Also, fructans have a sweet taste and are increasingly used as low-calorie sweeteners and as functional food ingredients.
Accordingly, there is a great deal of interest in understanding fructan biosynthetic pathways. With the isolation of nucleic acid fragments encoding various enzymes involved in the pathway, it may be possible to engineer transgenic plants to produce desired levels of different types of useful and novel fructans.
SUMMARY OF THE INVENTION
The present invention concerns an isolated polynucleotide comprising: (a) a first nucleotide sequence encoding a first polypeptide comprising at least 58 amino acids, wherein the amino acid sequence of the first polypeptide and the amino acid sequence of SEQ ID NO: 12 have at least 90% or 95% identity based on the Clustal alignment method, (b) a second nucleotide sequence encoding a second polypeptide comprising at least 140 amino acids, wherein the amino acid sequence of the second polypeptide and the amino acid sequence of SEQ ID NO: 6 have at least 90% or 95% identity based on the Clustal alignment method, (c) a third nucleotide sequence encoding a third polypeptide comprising at least 471 amino acids, wherein the amino acid sequence of the third polypeptide and the amino acid sequence of SEQ ID NO: 10 have at least 95% identity based on the Clustal alignment method, (d) a fourth nucleotide sequence encoding a fourth polypeptide comprising at least 495 amino acids, wherein the amino acid sequence of the fourth polypeptide and the amino acid sequence of SEQ ID NO: 8 have at least 95% identity based on the Clustal alignment method, (e) a fifth nucleotide sequence encoding a fifth polypeptide comprising at least 600 amino acids, wherein the amino acid sequence of the fifth polypeptide and the amino acid sequence of SEQ ID NO: 2 have at least 85%, 90%, or 95% identity based on the Clustal alignment method, (f) a sixth nucleotide sequence encoding a sixth polypeptide comprising at least 600 amino acids, wherein the amino acid sequence of the sixth polypeptide and the amino acid sequence of SEQ ID NO: 4 or SEQ ID NO: 14 have at least 90% or 95% identity based on the Clustal alignment method, (g) a seventh nucleotide sequence encoding a seventh polypeptide comprising at least 630 amino acids, wherein the amino acid sequence of the seventh polypeptide and the amino acid sequence of SEQ ID NO: 16 have at least 97% identity based on the Clustal alignment method, or (h) the complement of the first, second, third, fourth, fifth, sixth, or seventh nucleotide sequence, wherein the complement and the first, second, third, fourth, fifth, sixth, or seventh nucleotide sequence contain the same number of nucleotides and are 100% complementary.
In a second embodiment, the first polypeptide preferably comprises the amino acid sequence of SEQ ID NO: 12, the second polypeptide preferably comprises the amino acid sequence of SEQ ID NO: 6, the third polypeptide preferably comprises the amino acid sequence of SEQ ID NO: 10, the fourth polypeptide preferably comprises the amino acid sequence of SEQ ID NO: 8, the fifth polypeptide preferably comprises the amino acid sequence of SEQ ID NO: 2, the sixth polypeptide preferably comprises the amino acid sequence of SEQ ID NO: 4 or SEQ ID NO: 14, and the seventh polypeptide preferably comprises the amino acid sequence of SEQ ID NO: 16.
In a third embodiment, the first nucleotide sequence preferably comprises the nucleotide sequence of SEQ ID NO: 11, the second nucleotide sequence preferably comprises the nucleotide sequence of SEQ ID NO: 5, the third nucleotide sequence preferably comprises the nucleotide sequence of SEQ ID NO: 9, the fourth nucleotide sequence preferably comprises the nucleotide sequence of SEQ ID NO: 7, the fifth nucleotide sequence preferably comprises the nucleotide sequence of SEQ ID NO: 1, the sixth nucleotide sequence preferably comprises the nucleotide sequence of SEQ ID NO: 3 or SEQ ID NO: 13, and the seventh nucleotide sequence preferably comprises the nucleotide sequence of SEQ ID NO: 15.
In a fourth embodiment, the first, second, third, fourth, fifth, sixth, and seventh polypeptides preferably are fructosyltranferases.
In a fifth embodiment, the first, third and fourth polypeptides preferably are 6-SFT, the second and fifth polypeptides preferably are 1-FFT, the sixth polypeptide preferably is 1-FFT or 1-SST, and the seventh polypeptide preferably is 1-SST.
In a s
Allen Stephen M.
Caimi Perry G.
Stoop Johan M.
Bui Phuong T.
E. I. du Pont de Nemours and Company
Kallis Russell
LandOfFree
Fructan biosynthetic enzymes does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fructan biosynthetic enzymes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fructan biosynthetic enzymes will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3230275