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

3QTC の概要

• エントリーDOI: 10.2210/pdb3qtc/pdb
• 分子名称: Pyrrolysyl-tRNA synthetase, MAGNESIUM ION, O-methyl-L-tyrosine, ... (6 entities in total)
• 機能のキーワード: pyrrolysyl-trna synthetase, aminoacyl-trna synthetase, atp binding, o-methyl tyrosine binding, magnesium binding, aminoacylation, esterification, ligase
• 由来する生物種: Methanosarcina mazei (Methanosarcina frisia)
• 細胞内の位置: Cytoplasm (By similarity): Q8PWY1
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 34555.75

構造登録者

Dellas, N.,Takimoto, J.K.,Noel, J.P.,Wang, L. (登録日: 2011-02-22, 公開日: 2011-05-25, 最終更新日: 2023-12-06)

主引用文献

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

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: 21545173
DOI: 10.1021/cb200057a

実験手法

X-RAY DIFFRACTION (1.75 Å)