5T7D
Crystal structure of Streptomyces hygroscopicus bialaphos resistance (BAR) protein in complex with acetyl coenzyme A
Summary for 5T7D
| Entry DOI | 10.2210/pdb5t7d/pdb |
| Related | 5T7E |
| Descriptor | Phosphinothricin N-acetyltransferase, ACETYL COENZYME *A, ACETATE ION, ... (4 entities in total) |
| Functional Keywords | gcn5-related n-acetyltransferases phosphinothricin-deactivating activity, transferase |
| Biological source | Streptomyces hygroscopicus |
| Total number of polymer chains | 4 |
| Total formula weight | 88834.84 |
| Authors | Christ, B.,Weng, J.K. (deposition date: 2016-09-04, release date: 2017-06-07, Last modification date: 2024-05-22) |
| Primary citation | 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 Cited by 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: 29180815DOI: 10.1038/s41477-017-0061-1 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.4 Å) |
Structure validation
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