Structural requirements for the ubiquitin-associated domain of the mRNA export factor Mex67 to bind its specific targets, the transcription elongation THO complex component Hpr1 and nucleoporin FXFG repeats
| Autor: | Christoph Brockmann, David Neuhaus, Gilles Divita, Catherine Dargemont, Murray Stewart, Maria Hobeika, Florian Gruessing |
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| Rok vydání: | 2009 |
| Předmět: |
Models
Molecular Repetitive Sequences Amino Acid Nucleocytoplasmic Transport Proteins Saccharomyces cerevisiae Proteins THO complex Protein Conformation RNA-binding protein Plasma protein binding Saccharomyces cerevisiae Biology Crystallography X-Ray Biochemistry Fluorescence 03 medical and health sciences Structure-Activity Relationship Protein structure Nuclear pore Binding site Nuclear export signal Molecular Biology Nuclear Magnetic Resonance Biomolecular 030304 developmental biology 0303 health sciences Protein Synthesis Post-Translational Modification and Degradation 030302 biochemistry & molecular biology Nuclear Proteins RNA-Binding Proteins Biological Transport Cell Biology Peptide Fragments Nuclear Pore Complex Proteins Solutions Biophysics Nucleoporin Protein Binding |
| Zdroj: | The Journal of biological chemistry. 284(26) |
| ISSN: | 0021-9258 |
| Popis: | The ubiquitin-associated (UBA) domain of the principal Saccharomyces cerevisiae mRNA nuclear export factor, Mex67, can bind both nuclear pore protein (nucleoporin) FG repeats and Hpr1, a component of the TREX·THO complex that functions to link transcription and export. Using fluorescence resonance energy transfer-based assays, we show here that Hpr1 and the FG repeats interact with overlapping binding sites on the Mex67 UBA domain. We present the solution structure of the Mex67 UBA domain (UBA-Mex67) complexed with a FXFG nucleoporin peptide and define residues engaged in the interaction and those involved in the FXFG-induced conformational change. We show by NMR titration that the binding of Hpr1 produces analogous changes in chemical shifts in similar regions of the UBA domain. Together the data presented here indicate that both Hpr1 and FXFG nucleoporins may bind in a similar way to the UBA-Mex67 domain. However, whereas binding of Hpr1 allows UBA-Mex67 to interact with tetra-ubiquitin, the complex between UBA-Mex67 and FXFG is unable to bind mono- or tetra-ubiquitin, suggesting that both substrate binding and also the nature of the substrate may influence the affinity of the UBA-Mex67 domain for ubiquitin. |
| Databáze: | OpenAIRE |
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