3QTC
Crystal structure of the catalytic domain of MmOmeRS, an O-methyl tyrosyl-tRNA synthetase evolved from Methanosarcina mazei PylRS, complexed with O-methyl tyrosine and AMP-PNP
Summary for 3QTC
| Entry DOI | 10.2210/pdb3qtc/pdb |
| Descriptor | Pyrrolysyl-tRNA synthetase, MAGNESIUM ION, O-methyl-L-tyrosine, ... (6 entities in total) |
| Functional Keywords | pyrrolysyl-trna synthetase, aminoacyl-trna synthetase, atp binding, o-methyl tyrosine binding, magnesium binding, aminoacylation, esterification, ligase |
| Biological source | Methanosarcina mazei (Methanosarcina frisia) |
| Cellular location | Cytoplasm (By similarity): Q8PWY1 |
| Total number of polymer chains | 1 |
| Total formula weight | 34555.75 |
| Authors | Dellas, N.,Takimoto, J.K.,Noel, J.P.,Wang, L. (deposition date: 2011-02-22, release date: 2011-05-25, Last modification date: 2023-12-06) |
| Primary citation | Takimoto, J.K.,Dellas, N.,Noel, J.P.,Wang, L. Stereochemical Basis for Engineered Pyrrolysyl-tRNA Synthetase and the Efficient in Vivo Incorporation of Structurally Divergent Non-native Amino Acids. Acs Chem.Biol., 6:733-743, 2011 Cited by PubMed Abstract: Unnatural amino acids (Uaas) can be translationally incorporated into proteins in vivo using evolved tRNA/aminoacyl-tRNA synthetase (RS) pairs, affording chemistries inaccessible when restricted to the 20 natural amino acids. To date, most evolved RSs aminoacylate Uaas chemically similar to the native substrate of the wild-type RS; these conservative changes limit the scope of Uaa applications. Here, we adapt Methanosarcina mazei PylRS to charge a noticeably disparate Uaa, O-methyl-l-tyrosine (Ome). In addition, the 1.75 Å X-ray crystal structure of the evolved PylRS complexed with Ome and a non-hydrolyzable ATP analogue reveals the stereochemical determinants for substrate selection. Catalytically synergistic active site mutations remodel the substrate-binding cavity, providing a shortened but wider active site. In particular, mutation of Asn346, a residue critical for specific selection and turnover of the Pyl chemical core, accommodates different side chains while the central role of Asn346 in aminoacylation is rescued through compensatory hydrogen bonding provided by A302T. This multifaceted analysis provides a new starting point for engineering PylRS to aminoacylate a significantly more diverse selection of Uaas than previously anticipated. PubMed: 21545173DOI: 10.1021/cb200057a PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.75 Å) |
Structure validation
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