5U6M

Crystal structure of UDP-glucosyltransferase, UGT74F2, with UDP and salicylic acid

5U6M の概要

• エントリーDOI: 10.2210/pdb5u6m/pdb
• 関連するPDBエントリー: 5U6N 5U6S
• 分子名称: UDP-glycosyltransferase 74F2, beta-D-glucopyranose, URIDINE-5'-DIPHOSPHATE, ... (5 entities in total)
• 機能のキーワード: udp-glucosyltransferase, salicylic acid, salicylic acid glucoside, salicylic acid ester, transferase
• 由来する生物種: Arabidopsis thaliana (Mouse-ear cress)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 103088.12

構造登録者

George Thompson, A.M.,Iancu, C.V.,Dean, J.V.,Choe, J. (登録日: 2016-12-08, 公開日: 2017-05-03, 最終更新日: 2020-07-29)

主引用文献

George Thompson, A.M.,Iancu, C.V.,Neet, K.E.,Dean, J.V.,Choe, J.Y.
Differences in salicylic acid glucose conjugations by UGT74F1 and UGT74F2 from Arabidopsis thaliana.
Sci Rep, 7:46629-46629, 2017

PubMed Abstract: Salicylic acid (SA) is a signaling molecule utilized by plants in response to various stresses. Through conjugation with small organic molecules such as glucose, an inactive form of SA is generated which can be transported into and stored in plant vacuoles. In the model organism Arabidopsis thaliana, SA glucose conjugates are formed by two homologous enzymes (UGT74F1 and UGT74F2) that transfer glucose from UDP-glucose to SA. Despite being 77% identical and with conserved active site residues, these enzymes catalyze the formation of different products: UGT74F1 forms salicylic acid glucoside (SAG), while UGT74F2 forms primarily salicylic acid glucose ester (SGE). The position of the glucose on the aglycone determines how SA is stored, further metabolized, and contributes to a defense response. We determined the crystal structures of the UGT74F2 wild-type and T15S mutant enzymes, in different substrate/product complexes. On the basis of the crystal structures and the effect on enzyme activity of mutations in the SA binding site, we propose the catalytic mechanism of SGE and SAG formation and that SA binds to the active site in two conformations, with each enzyme selecting a certain binding mode of SA. Additionally, we show that two threonines are key determinants of product specificity.

PubMed: 28425481
DOI: 10.1038/srep46629

実験手法

X-RAY DIFFRACTION (2.568 Å)