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Crystal structure of human CRM1, covalently modified by 2-mercaptoethanol on Cys528, in complex with RanGTP
Alaa Shaikhqasem1, Kerstin Schmitt2, Oliver Valerius2
1Department for Molecular Structural Biology, Georg-August-Universität Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany.
Abstract:
CRM1 is a nuclear export receptor that has been intensively targeted over the last decade for the development of antitumor and antiviral drugs. Structural analysis of several inhibitor compounds bound to CRM1 revealed that their mechanism of action relies on the covalent modification of a critical cysteine residue (Cys528 in the human receptor) located in the nuclear export signal-binding cleft. This study presents the crystal structure of human CRM1, covalently modified by 2-mercaptoethanol on Cys528, in complex with RanGTP at 2.58 Å resolution. The results demonstrate that buffer components can interfere with the characterization of cysteine-dependent inhibitor compounds.
Insights
Nuclear export receptor CRM1 is a target for cancer and antiviral drugs. This study reveals buffer components can interfere with characterizing cysteine-dependent CRM1 inhibitors.
Area of Science:
- Molecular Biology
- Structural Biology
- Biochemistry
Background:
- The nuclear export receptor CRM1 (Chromosome Region Maintenance 1) is a crucial target for developing antitumor and antiviral therapeutics.
- Inhibitor compounds targeting CRM1 often function by covalently modifying a critical cysteine residue (Cys528) within the nuclear export signal-binding cleft.
Purpose of the Study:
- To elucidate the structural basis of CRM1 inhibition by characterizing the crystal structure of human CRM1 covalently modified by 2-mercaptoethanol on Cys528.
- To investigate the complex of CRM1 with RanGTP and understand the structural implications of cysteine modification.
Main Methods:
- X-ray crystallography was employed to determine the structure of human CRM1 in complex with RanGTP.
- The CRM1 structure was resolved at a resolution of 2.58 Å after covalent modification with 2-mercaptoethanol at Cys528.
Main Results:
- The crystal structure reveals the detailed atomic arrangement of human CRM1 covalently modified by 2-mercaptoethanol at Cys528 in complex with RanGTP.
- The findings highlight that buffer components can inadvertently interact with and modify cysteine residues, potentially interfering with the accurate characterization of cysteine-dependent CRM1 inhibitor compounds.
Conclusions:
- The structural data provides insights into the binding of RanGTP to CRM1 and the consequences of cysteine modification.
- This study underscores the importance of carefully considering buffer composition during the structural and biochemical characterization of CRM1 inhibitors to avoid artifacts and ensure reliable drug development.
