5T7D

Crystal structure of Streptomyces hygroscopicus bialaphos resistance (BAR) protein in complex with acetyl coenzyme A

5T7D の概要

• エントリーDOI: 10.2210/pdb5t7d/pdb
• 関連するPDBエントリー: 5T7E
• 分子名称: Phosphinothricin N-acetyltransferase, ACETYL COENZYME *A, ACETATE ION, ... (4 entities in total)
• 機能のキーワード: gcn5-related n-acetyltransferases phosphinothricin-deactivating activity, transferase
• 由来する生物種: Streptomyces hygroscopicus
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 88834.84

構造登録者

Christ, B.,Weng, J.K. (登録日: 2016-09-04, 公開日: 2017-06-07, 最終更新日: 2024-05-22)

主引用文献

Christ, B.,Hochstrasser, R.,Guyer, L.,Francisco, R.,Aubry, S.,Hortensteiner, S.,Weng, J.K.
Non-specific activities of the major herbicide-resistance gene BAR.
Nat Plants, 3:937-945, 2017

PubMed Abstract: Bialaphos resistance (BAR) and phosphinothricin acetyltransferase (PAT) genes, which convey resistance to the broad-spectrum herbicide phosphinothricin (also known as glufosinate) via N-acetylation, have been globally used in basic plant research and genetically engineered crops . Although early in vitro enzyme assays showed that recombinant BAR and PAT exhibit substrate preference toward phosphinothricin over the 20 proteinogenic amino acids , indirect effects of BAR-containing transgenes in planta, including modified amino acid levels, have been seen but without the identification of their direct causes . Combining metabolomics, plant genetics and biochemical approaches, we show that transgenic BAR indeed converts two plant endogenous amino acids, aminoadipate and tryptophan, to their respective N-acetylated products in several plant species. We report the crystal structures of BAR, and further delineate structural basis for its substrate selectivity and catalytic mechanism. Through structure-guided protein engineering, we generated several BAR variants that display significantly reduced non-specific activities compared with its wild-type counterpart in vivo. The transgenic expression of enzymes can result in unintended off-target metabolism arising from enzyme promiscuity. Understanding such phenomena at the mechanistic level can facilitate the design of maximally insulated systems featuring heterologously expressed enzymes.

PubMed: 29180815
DOI: 10.1038/s41477-017-0061-1

実験手法

X-RAY DIFFRACTION (1.4 Å)