1WXO

Structure of Archaeal Trans-Editing Protein AlaX in complex with zinc

Summary for 1WXO

• Entry DOI: 10.2210/pdb1wxo/pdb
• Related: 1V7O 1WNU
• Descriptor: alanyl-tRNA synthetase, ZINC ION (3 entities in total)
• Functional Keywords: hydrolase, trans-editing
• Biological source: Pyrococcus horikoshii
• Cellular location: Cytoplasm (Probable): O58307
• Total number of polymer chains: 3
• Total formula weight: 54745.40

Authors

Sokabe, M.,Okada, A.,Nakashima, T.,Yao, M.,Tanaka, I. (deposition date: 2005-01-27, release date: 2005-07-26, Last modification date: 2023-10-25)

Primary citation

Sokabe, M.,Okada, A.,Yao, M.,Nakashima, T.,Tanaka, I.
Molecular basis of alanine discrimination in editing site
Proc.Natl.Acad.Sci.Usa, 102:11669-11674, 2005

PubMed Abstract: AlaX is the homologue of the class II alanyl-tRNA synthetase editing domain and has been shown to exhibit autonomous editing activity against mischarged tRNA(Ala). Here, we present the structures of AlaX from the archaeon Pyrococcus horikoshii in apo form, complexed with zinc, and with noncognate amino acid l-serine and zinc. Together with mutational analysis, we demonstrated that the conserved Thr-30 hydroxyl group located near the beta-methylene of the bound serine is responsible for the discrimination of noncognate serine from cognate alanine, based on their chemical natures. Furthermore, we confirmed that the conserved Gln-584 in alanyl-tRNA synthetase, which corresponds to Thr-30 of AlaX, is also critical for discrimination. These observations strongly suggested conservation of the chemical discrimination among trans- and cis-editing of tRNA(Ala).

PubMed: 16087889
DOI: 10.1073/pnas.0502119102

Experimental method

X-RAY DIFFRACTION (1.88 Å)