The invention provides a polynucleotide sequence (e.g., a gene, e.g., DNA or RNA) encoding UGT1A1 (e.g., expressing human UGT1A1). The invention further provides a vector, such as an adeno-associated virus (AAV) vector (e.g., AAV8) having a vector genome including inverted terminal repeat sequences and a UGT1A1 coding sequence operably linked to one or more expression control sequences (e.g., expression control sequences including a liver-specific promoter). Also provided are compositions containing these AAV vectors and methods of treating Crigler-Nijjar syndrome type I, Crigler-Nijjar syndrome type II, and Gilbert syndrome.

Disclosed are steviol glycosides referred to as rebaudioside V and rebaudioside W. Also disclosed are methods for producing rebaudioside M (Reb M), rebausoside G (Reb G), rebaudioside KA (Reb KA), rebaudioside V (Reb V) and rebaudioside (Reb W).

Disclosed is a steviol glycoside referred to as rebaudioside D3. Rebaudioside D3 has five β-D-glucosyl units connected to the aglycone steviol. Also disclosed are methods for producing rebaudioside D3, a UDP-glycosyltransferase fusion enzyme, and methods for producing rebaudioside D and rebaudioside E.

The invention provides a polynucleotide sequence (e.g., a gene, e.g., DNA or RNA) encoding UGT1A1 (e.g., expressing human UGT1A1). The invention further provides a vector, such as an adeno-associated virus (AAV) vector (e.g., AAV8) having a vector genome including inverted terminal repeat sequences and a UGT1A1 coding sequence operably linked to one or more expression control sequences (e.g., expression control sequences including a liver-specific promoter). Also provided are compositions containing these AAV vectors and methods of treating Crigler-Nijjar syndrome type I, Crigler-Nijjar syndrome type II, and Gilbert syndrome.

Described in this application are enzymes (e.g., cucurbitadienol synthases (CDS), UDP-glycosyltransferases (UGT), C11 hydroxylases, epoxide hydrolases (EPH), squalene epoxidases, and/or cytochrome P450 reductases), host cells expressing the enzymes, and methods of producing mogrol precursors, mogrol, and/or mogrosides using such host cells.

Provided herein are compositions and methods for improved production of steviol glycosides in a host cell. In some embodiments, the host cell is genetically modified to comprise a heterologous nucleotide sequence encoding a Stevia rebaudiana kaurenoic acid hydroxylase. In some embodiments, the host cell further comprises one or more heterologous nucleotide sequence encoding further enzymes of a pathway capable of producing one or more steviol glycosides in the host cell. The compositions and methods described herein provide an efficient route for the heterologous production of steviol glycosides, including but not limited to, rebaudioside D and rebaudioside M.

Provided is a method for preparing Rebaudioside J using an enzymatic method, comprising using rebaudioside A as a substrate, and making the substrate, in the presence of a glycosyl donor, react under the catalysis of a UDP-glycosyltransferase-con-taining recombinant cell and/or UDP-glycosyltransferase prepared therefrom to generate Rebaudioside J.

Provided is a method for preparing rebaudioside N using an enzymatic method, comprising using rebaudioside A or rebaudioside J as a substrate, and making the substrate, in the presence of a glycosyl donor, react under the catalysis of a UDP-glycosyl-transferase and/or a UDP-glycosyltransferase-containing recombinant cell to generate rebaudioside N.

Disclosed are steviol glycosides referred to as rebaudioside V and rebaudioside W. Also disclosed are methods for producing rebaudioside M (Reb M), rebausoside G (Reb G), rebaudioside KA (Reb KA), rebaudioside V (Reb V) and rebaudioside (Reb W).

The present invention relates, in some aspects, to the production of steviol glycoside rebaudioside D4 through the use of rebaudioside E. In some aspects, the invention relates to mutant CP1 enzymes, mutant HV1 enzymes as well as host cells and methods utilizing such enzymes, such as to produce rebaudioside D4.