Reaction: (1) dimethylallyl diphosphate + ADP = diphosphate + N6-(dimethylallyl)adenosine 5′-diphosphate
(2) dimethylallyl diphosphate + ATP = diphosphate + N6-(dimethylallyl)adenosine 5′-triphosphate
For diagram of reaction, click here
Other name(s): cytokinin synthase (ambiguous); isopentenyltransferase (ambiguous); 2-isopentenyl-diphosphate:ADP/ATP Δ2-isopentenyltransferase; adenylate isopentenyltransferase (ambiguous); dimethylallyl diphosphate:ATP/ADP isopentenyltransferase: IPT
Systematic name: dimethylallyl-diphosphate:ADP/ATP dimethylallyltransferase
Comments: Involved in the biosynthesis of cytokinins in plants. The IPT4 isoform from the plant Arabidopsis thaliana is specific for ADP and ATP [1]. Other isoforms, such as IPT1 from Arabidopsis thaliana [1,2] and the enzyme from the common hop, Humulus lupulus [3], also have a lower activity with AMP (cf. EC 2.5.1.27, adenylate dimethylallyltransferase).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Kakimoto, T. Identification of plant cytokinin biosynthetic enzymes as dimethylallyl diphosphate:ATP/ADP isopentenyltransferases. Plant Cell Physiol 42 (2001) 677-685. [PMID: 11479373]
2. Takei, K., Sakakibara, H. and Sugiyama, T. Identification of genes encoding adenylate isopentenyltransferase, a cytokinin biosynthesis enzyme, in Arabidopsis thaliana. J. Biol. Chem. 276 (2001) 26405-26410. [PMID: 11313355]
3. Sakano, Y., Okada, Y., Matsunaga, A., Suwama, T., Kaneko, T., Ito, K., Noguchi, H. and Abe, I. Molecular cloning, expression, and characterization of adenylate isopentenyltransferase from hop (Humulus lupulus L.). Phytochemistry 65 (2004) 2439-2446. [PMID: 15381407]