Charged and uncharged tRNAs adopt distinct conformations when complexed with human tryptophanyl-tRNA synthetaseCharged and uncharged tRNAs adopt distinct conformations when complexed with human tryptophanyl-tRNA synthetase

Structural highlights

2azx is a 4 chain structure with sequence from Bos taurus and Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.8Å
Ligands:, , , ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

SYWC_HUMAN Isoform 1, isoform 2 and T1-TrpRS have aminoacylation activity while T2-TrpRS lacks it. Isoform 2, T1-TrpRS and T2-TrpRS possess angiostatic activity whereas isoform 1 lacks it. T2-TrpRS inhibits fluid shear stress-activated responses of endothelial cells. Regulates ERK, Akt, and eNOS activation pathways that are associated with angiogenesis, cytoskeletal reorganization and shear stress-responsive gene expression.[1] [2] [3] [4]

Evolutionary Conservation

 

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Aminoacylation of tRNA is the first step of protein synthesis. Here, we report the co-crystal structure of human tryptophanyl-tRNA synthetase and tRNATrp. This enzyme is reported to interact directly with elongation factor 1alpha, which carries charged tRNA to the ribosome. Crystals were generated from a 50/50% mixture of charged and uncharged tRNATrp. These crystals captured two conformations of the complex, which are nearly identical with respect to the protein and a bound tryptophan. They are distinguished by the way tRNA is bound. In one, uncharged tRNA is bound across the dimer, with anticodon and acceptor stem interacting with separate subunits. In this cross-dimer tRNA complex, the class I enzyme has a class II-like tRNA binding mode. This structure accounts for biochemical investigations of human TrpRS, including species-specific charging. In the other conformation, presumptive aminoacylated tRNA is bound only by the anticodon, the acceptor stem being free and having space to interact precisely with EF-1alpha, suggesting that the product of aminoacylation can be directly handed off to EF-1alpha for the next step of protein synthesis.

Two conformations of a crystalline human tRNA synthetase-tRNA complex: implications for protein synthesis.,Yang XL, Otero FJ, Ewalt KL, Liu J, Swairjo MA, Kohrer C, RajBhandary UL, Skene RJ, McRee DE, Schimmel P EMBO J. 2006 Jun 21;25(12):2919-29. Epub 2006 May 25. PMID:16724112[5]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Wakasugi K, Slike BM, Hood J, Otani A, Ewalt KL, Friedlander M, Cheresh DA, Schimmel P. A human aminoacyl-tRNA synthetase as a regulator of angiogenesis. Proc Natl Acad Sci U S A. 2002 Jan 8;99(1):173-7. Epub 2002 Jan 2. PMID:11773626 doi:10.1073/pnas.012602099
  2. Bange FC, Flohr T, Buwitt U, Bottger EC. An interferon-induced protein with release factor activity is a tryptophanyl-tRNA synthetase. FEBS Lett. 1992 Mar 30;300(2):162-6. PMID:1373391
  3. Otani A, Slike BM, Dorrell MI, Hood J, Kinder K, Ewalt KL, Cheresh D, Schimmel P, Friedlander M. A fragment of human TrpRS as a potent antagonist of ocular angiogenesis. Proc Natl Acad Sci U S A. 2002 Jan 8;99(1):178-83. Epub 2002 Jan 2. PMID:11773625 doi:10.1073/pnas.012601899
  4. Tzima E, Reader JS, Irani-Tehrani M, Ewalt KL, Schwartz MA, Schimmel P. Biologically active fragment of a human tRNA synthetase inhibits fluid shear stress-activated responses of endothelial cells. Proc Natl Acad Sci U S A. 2003 Dec 9;100(25):14903-7. Epub 2003 Nov 20. PMID:14630953 doi:10.1073/pnas.2436330100
  5. Yang XL, Otero FJ, Ewalt KL, Liu J, Swairjo MA, Kohrer C, RajBhandary UL, Skene RJ, McRee DE, Schimmel P. Two conformations of a crystalline human tRNA synthetase-tRNA complex: implications for protein synthesis. EMBO J. 2006 Jun 21;25(12):2919-29. Epub 2006 May 25. PMID:16724112

2azx, resolution 2.80Å

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