1u7x: Difference between revisions
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'''crystal structure of a mutant M. jannashii tyrosyl-tRNA synthetase specific for O-methyl-tyrosine''' | {{Structure | ||
|PDB= 1u7x |SIZE=350|CAPTION= <scene name='initialview01'>1u7x</scene>, resolution 3.00Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=K:POTASSIUM ION'>K</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Tyrosine--tRNA_ligase Tyrosine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.1 6.1.1.1] | |||
|GENE= tyrS ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=2190 Methanocaldococcus jannaschii]) | |||
}} | |||
'''crystal structure of a mutant M. jannashii tyrosyl-tRNA synthetase specific for O-methyl-tyrosine''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1U7X is a [ | 1U7X is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Methanocaldococcus_jannaschii Methanocaldococcus jannaschii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1U7X OCA]. | ||
==Reference== | ==Reference== | ||
Crystal structures of apo wild-type M. jannaschii tyrosyl-tRNA synthetase (TyrRS) and an engineered TyrRS specific for O-methyl-L-tyrosine., Zhang Y, Wang L, Schultz PG, Wilson IA, Protein Sci. 2005 May;14(5):1340-9. PMID:[http:// | Crystal structures of apo wild-type M. jannaschii tyrosyl-tRNA synthetase (TyrRS) and an engineered TyrRS specific for O-methyl-L-tyrosine., Zhang Y, Wang L, Schultz PG, Wilson IA, Protein Sci. 2005 May;14(5):1340-9. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15840835 15840835] | ||
[[Category: Methanocaldococcus jannaschii]] | [[Category: Methanocaldococcus jannaschii]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: rossman fold]] | [[Category: rossman fold]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 14:28:26 2008'' | ||
Revision as of 15:28, 20 March 2008
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| , resolution 3.00Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Gene: | tyrS (Methanocaldococcus jannaschii) | ||||||
| Activity: | Tyrosine--tRNA ligase, with EC number 6.1.1.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
crystal structure of a mutant M. jannashii tyrosyl-tRNA synthetase specific for O-methyl-tyrosine
OverviewOverview
The Methanococcus jannaschii tRNA(Tyr)/TyrRS pair has been engineered to incorporate unnatural amino acids into proteins in E. coli. To reveal the structural basis for the altered specificity of mutant TyrRS for O-methyl-L-tyrosine (OMeTyr), the crystal structures for the apo wild-type and mutant M. jannaschii TyrRS were determined at 2.66 and 3.0 A, respectively, for comparison with the published structure of TyrRS complexed with tRNA(Tyr) and substrate tyrosine. A large conformational change was found for the anticodon recognition loop 257-263 of wild-type TyrRS upon tRNA binding in order to facilitate recognition of G34 of the anticodon loop through pi-stacking and hydrogen bonding interactions. Loop 133-143, which is close to the tRNA acceptor stem-binding site, also appears to be stabilized by interaction with the tRNA(Tyr). Binding of the substrate tyrosine results in subtle and cooperative movements of the side chains within the tyrosine-binding pocket. In the OMeTyr-specific mutant synthetase structure, the signature motif KMSKS loop and acceptor stem-binding loop 133-143 were surprisingly ordered in the absence of bound ATP and tRNA. The active-site mutations result in altered hydrogen bonding and steric interactions which favor binding of OMeTyr over L-tyrosine. The structure of the mutant and wild-type TyrRS now provide a basis for generating new active-site libraries to evolve synthetases specific for other unnatural amino acids.
About this StructureAbout this Structure
1U7X is a Single protein structure of sequence from Methanocaldococcus jannaschii. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of apo wild-type M. jannaschii tyrosyl-tRNA synthetase (TyrRS) and an engineered TyrRS specific for O-methyl-L-tyrosine., Zhang Y, Wang L, Schultz PG, Wilson IA, Protein Sci. 2005 May;14(5):1340-9. PMID:15840835
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