Selective oxidation of 5-methylcytosine by TET-family proteins
The present invention provides for novel methods for regulating and detecting the cytosine methylation status of DNA. The invention is based upon identification of a novel and surprising catalytic activity for the family of TET proteins, namely TET1, TET2, TET3, and CXXC4. The novel activity is related to the enzymes being capable of converting the cytosine nucleotide 5-methylcytosine into 5-hydroxymethylcytosine by hydroxylation.
1. A kit for the detection and purification of methylcytosine and 5-hydroxymethylcytosine for use in downstream applications, the kit comprising:
(a) one or more catalytically active TET family enzymes, functional TET family derivatives, or TET catalytically active fragments thereof for the conversion of methylcytosine to 5-hydroxymethylcytosine;
(b) one or more enzymes encoded by bacteriophages of the “T even” family;
(c) one or more glucose or glucose-derivative donor substrates;
(d) one or more proteins to detect glucose or glucose-derivative modified nucleotides;
(e) standard DNA purification columns, buffers, and substrate solutions; and
(f) packaging materials and instructions therein to use said kits,
wherein the enzyme encoded by bacteriophages of the “T even” family is selected from the group consisting of alpha-glucosyltransferases, beta-glucosyltransferases, and beta-glucosyl-alpha-glucosyl-transferases.
2. The kit of claim 1 , wherein the alpha-glucosyltransferase is encoded by a bacteriophage selected from the group consisting of T2, T4, and T6 bacteriophages.
3. The kit of claim 1 , wherein the beta-glucosyltransferase is encoded by a bacteriophage selected from T4 bacteriophages.
4. The kit of claim 1 , wherein the beta-glucosyl-alpha-glucosyl-transferase is encoded by a bacteriophage selected from the group consisting of T2 and T6 bacteriophages.
5. The kit of claim 1 , wherein the glucose or glucose-derivative donor substrate is uridine diphosphate glucose (UDPG).
6. The kit of claim 1 , wherein the glucose or glucose-derivative donor substrate is radiolabeled.
7. The kit of claim 6 , wherein the uridine diphosphate glucose is radiolabeled with 14C or 3H.
8. The kit of claim 1 , wherein the protein to detect glucose or glucose-derivative modified nucleotides is a lectin, an antibody or an antigen binding fragment thereof, or an enzyme.
9. The kit of claim 8 , wherein the protein recognizes the glucose or glucose-derivative only in the context of 5-hydroxymethylcytosine.
10. The kit of claim 8 , wherein the protein is modified with at least one tag.
11. The kit of claim 10 , wherein the tag is a biotin molecule, a bead, a gold particle, or a fluorescent molecule.
12. The kit of claim 8 , wherein the enzyme is a hexokinase or a beta-glucosyl-alpha-glucosyl-transferase.
13. The kit of claim 8 , wherein the lectin is Musa acuminata lectin (BanLec).
14. The kit of claim 8 , wherein the lectin is modified with a gold particle or a fluorescent tag.