2ZE7

Crystal Structure of adenosine phosphate-isopentenyltransferase complexed with zinc ion and substrate analog, DMASPP

2ZE7 の概要

• エントリーDOI: 10.2210/pdb2ze7/pdb
• 関連するPDBエントリー: 2zE5 2zE6 2zE8
• 分子名称: Isopentenyl transferase, ZINC ION, DIMETHYLALLYL S-THIOLODIPHOSPHATE, ... (5 entities in total)
• 機能のキーワード: transferase, crown gall tumor, cytokinin biosynthesis
• 由来する生物種: Agrobacterium tumefaciens
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 29583.01

構造登録者

Sakakibara, H. (登録日: 2007-12-06, 公開日: 2008-02-05, 最終更新日: 2024-03-13)

主引用文献

Sugawara, H.,Ueda, N.,Kojima, M.,Makita, N.,Yamaya, T.,Sakakibara, H.
Structural insight into the reaction mechanism and evolution of cytokinin biosynthesis.
Proc.Natl.Acad.Sci.Usa, 105:2734-2739, 2008

PubMed Abstract: The phytohormone cytokinin regulates plant growth and development. This hormone is also synthesized by some phytopathogenic bacteria, such as Agrobacterium tumefaciens, and is as a key factor in the formation of plant tumors. The rate-limiting step of cytokinin biosynthesis is catalyzed by adenosine phosphate-isopentenyltransferase (IPT). Agrobacterium IPT has a unique substrate specificity that enables it to increase trans-zeatin production by recruiting a metabolic intermediate of the host plant's biosynthetic pathway. Here, we show the crystal structures of Tzs, an IPT from A. tumefaciens, complexed with AMP and a prenyl-donor analogue, dimethylallyl S-thiodiphosphate. The structures reveal that the carbon-nitrogen-based prenylation proceeds by the SN2-reaction mechanism. Site-directed mutagenesis was used to determine the amino acid residues, Asp-173 and His-214, which are responsible for differences in prenyl-donor substrate specificity between plant and bacterial IPTs. IPT and the p loop-containing nucleoside triphosphate hydrolases likely evolved from a common ancestral protein. Despite structural similarities, IPT has evolved a distinct role in which the p loop transfers a prenyl moiety in cytokinin biosynthesis.

PubMed: 18258747
DOI: 10.1073/pnas.0707374105

実験手法

X-RAY DIFFRACTION (2.1 Å)