Abstract: Two sequences of a nucleic acid isolated from a cDNA library of the flowering plant Adonis aestivalis is disclosed (SEQ ID NO: 5). The first DNA sequence, referred to as AdKC28, encodes for a polypeptide (SEQ ID NO: 6) that acts in conjunction with polypeptides encoded by either one of two other closely-related Adonis aestivalis cDNAs, AdKeto1 (SEQ ID NO: 1) and AdKeto2 (SEQ ID NO: 2), to convert ?-carotene (?,?-carotene) into astaxanthin (3,3?-dihydroxy-4,4?-diketo-?, ?-carotene). A second DNA sequence, referred to as AdKCl 7 is also disclosed (FIG. 9). Together, these Adonis aestivalis cDNAs, when operably linked to promoters appropriate to the transgenic host, enable the production of astaxanthin and other carotenoids with 3-hydroxy-4-keto-?-rings in a variety of host cells and organisms.

Abstract: Two sequences of a nucleic acid isolated from a cDNA library of the flowering plant Adonis aestivalis is disclosed (SEQ ID NO: 5). The first DNA sequence, referred to as AdKC28, encodes for a polypeptide (SEQ ID NO: 6) that acts in conjunction with polypeptides encoded by either one of two other closely-related Adonis aestivalis cDNAs, AdKeto1 (SEQ ID NO: 1) and AdKeto2 (SEQ ID NO: 2), to convert ?-carotene (?,?-carotene) into astaxanthin (3,3?-dihydroxy-4,4?-diketo-?, ?-carotene). A second DNA sequence, referred to as AdKCl 7 is also disclosed (FIG. 9). Together, these Adonis aestivalis cDNAs, when operably linked to promoters appropriate to the transgenic host, enable the production of astaxanthin and other carotenoids with 3-hydroxy-4-keto-?-rings in a variety of host cells and organisms.

Abstract: The invention relates to methods for mapping and characterizing catalytic domains in enzymes, preferably plant enzymes and those enzymes within the carotene synthesis family and more specifically &egr;-cyclase enzymes regulating formation of &egr;,&egr;-carotene. The methods include reverse PCR and site-directed mutagenesis for generating chimera and truncations or site-directed mutations of enzymes, respectively. These chimera, truncations or site directed mutants of &egr;-cyclase enzymes are useful in the characterization of the sequence residues conferring catalytic domains for the enzymes, and more specifically, the identification of single residues regulating catalytic activity for enzymes that are important in plant growth and photosynthesis. Chimeric enzymes generated by the methods of the invention can also be used to create transgenci hosts which are augmentated in their expression of specific carotene products.

Abstract: The present invention relates to the DNA sequence for eukaryotic genes encoding &egr; cyclase isolated from romaine lettuce as well as vectors containing the same and hosts transformed with said vectors. The present invention provides methods for controlling the ratio of various carotenoids in a host and to the production of novel carotenoid pigments. The present invention also provides a method for treating disease by administering carotenoids obtained from transformed hosts, or by administering a composition containing the transformed hosts.

Abstract: Nucleic acid sequences encoding ∈-cyclase, isopentenyl pyrophosphate isomerase and &bgr;-carotene hydroxylase as well as vectors containing the same and hosts transformed with the vectors. Methods for controlling the ratio of various carotenoids in a host and for the production of novel carotenoid pigments. The present invention also provides a method for screening for eukaryotic genes encoding carotenoid biosynthesis, and for modifying the disclosed enzymes.

Abstract: A purified nucleic acid sequence which encodes for a protein having ketolase enzyme activity and has the nucleic acid sequence of SEQ ID NO: 1 or 3, or has a sequence which encodes the amino acid sequence of SEQ ID NO: 2 or 4, as well as vectors and host cells containing them. Methods of use of the nucleic acid sequences to produce ketocarotenoid in host cells and methods of use of the nucleic acid sequences to modify the production of carotenoids in a host cell are included.

Abstract: The present invention describes the DNA sequence for eukaryotic genes encoding &egr; cyclase, isopentenyl pyrophosphate (IPP) isomerase and &bgr;-carotene hydroxylase as well as vectors containing the same and host cells transformed with said vectors. The &egr; cyclase and &bgr;-carotene hydroxylase genes disclosed include those from A. thaliana; the IPP isomerase genes disclosed include those from A. thaliana, H. pluvialis, and marigold. The present invention also provides methods for controlling the ratio of various carotenoids in a host cell and for the production of novel carotenoid pigments. The present invention also provides a method for screening for eukaryotic genes encoding carotenoid biosynthesis enzymes.

Abstract: Nucleic acid sequences encoding ∈-cyclase, isopentenyl pyrophosphate isomerase and &bgr;-carotene hydroxylase as well as vectors containing the same and hosts transformed with the vectors. Methods for controlling the ratio of various carotenoids in a host and for the production of novel carotenoid pigments. The present invention also provides a method for screening for eukaryotic genes encoding carotenoid biosynthesis, and for modifying the disclosed enzymes.

Abstract: The present invention relates to the DNA sequence for eukaryotic genes encoding &egr; cyclase isolated from romaine lettuce as well as vectors containing the same and hosts transformed with said vectors. The present invention provides methods for controlling the ratio of various carotenoids in a host and to the production of novel carotenoid pigments. The present invention also provides a method for treating disease by administering carotenoids obtained from transformed hosts, or by administering a composition containing the transformed hosts.

Abstract: The present invention describes the gene encoding beta-cyclase from marigolds. In particular, the present invention provides the DNA sequence for the gene encoding marigold beta-cyclase as well as vectors containing the same and bacteria and plants transformed with the vectors.

Abstract: The present invention also describes the DNA sequence for eukaryotic genes encoding .epsilon. cyclase, isopentenyl pyrophosphate isomerase and .beta.-carotene hydroxylase as well as vectors containing the same and hosts transformed with said vectors. The present invention provides methods for controlling the ratio of various carotenoids in a host and for the production of novel carotenoid pigments. The present invention also provides a method for screening for eukaryotic genes encoding carotenoid biosynthesis.