Abstract
Phosphinothricin inhibits plant glutamine synthetase and is used as a herbicide. Streptomyces hygroscopicus and Streptomyces viridochromogenes, which produce phosphinothricin naturally, encode acetyltransferases that confer phosphinothricin resistance. In the Pseudomonas genome database, a number of proteins have been annotated as phosphinothricin acetyltransferases and putative phosphinothricin acetyltransferases. One such protein is PSPTO_3321 from P. syringae, a strain that causes tomato speck.
Here, we reveal that PSPTO_3321 from P. syringae, termed syr_pat, is a phosphinothricin acetyltransferase, and also retains a lower level of activity against the structurally similar substrate methionine sulfoximine. We solved a 1.6Å resolution crystal structure of syr_pat alone and a 2.5Å resolution structure for a complex with L-phosphinothricin. We also characterised active site mutants, providing insights into substrate specificity. Our work now provides a basis for further study of the reaction mechanism.
Here, we reveal that PSPTO_3321 from P. syringae, termed syr_pat, is a phosphinothricin acetyltransferase, and also retains a lower level of activity against the structurally similar substrate methionine sulfoximine. We solved a 1.6Å resolution crystal structure of syr_pat alone and a 2.5Å resolution structure for a complex with L-phosphinothricin. We also characterised active site mutants, providing insights into substrate specificity. Our work now provides a basis for further study of the reaction mechanism.
| Original language | English |
|---|---|
| Article number | 151539 |
| Journal | Biochemical and Biophysical Research Communications |
| Volume | 755 |
| DOIs | |
| Publication status | Published - 1 Apr 2025 |