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Understanding the interaction of antibodies and transcription factors with their ligands through structural biology
Škerlová, Jana
Understanding protein function highly benefits from the knowledge of its three-dimensional structure, especially in the case of protein-ligand complexes. Structural biology methods such as X-ray crystallography, SAXS and NMR are therefore widely used for structural studies of protein-ligand interaction. In this work, these methods were used to understand two biological processes involving protein interactions: X-ray structural analysis was used to study binding of effector molecule to a prokaryotic transcription factor. NMR and SAXS techniques were used to study interaction of a monoclonal antibody with its protein antigen. Transcriptional regulator DeoR negatively regulates the expression of catabolic genes for the utilization of deoxyribonucleosides and deoxyribose in Bacillus subtilis. DeoR comprises an N-terminal DNA-binding domain and a C-terminal effector-binding domain (C-DeoR), and its function is regulated by binding of a small-molecular effector deoxyribose-5-phosphate. We determined crystal structures of C-DeoR both in the free form and in complex with deoxyribose-5-phosphate. Structural analysis revealed unique covalent binding of effector molecule through a reversible Schiff-base double bond with an effector-binding-site lysine residue. The physiological nature of this binding mode was...
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Understanding the interaction of antibodies and transcription factors with their ligands through structural biology
Škerlová, Jana ; Maloy Řezáčová, Pavlína (advisor) ; Hrabal, Richard (referee) ; Obšil, Tomáš (referee)
Understanding protein function highly benefits from the knowledge of its three-dimensional structure, especially in the case of protein-ligand complexes. Structural biology methods such as X-ray crystallography, SAXS and NMR are therefore widely used for structural studies of protein-ligand interaction. In this work, these methods were used to understand two biological processes involving protein interactions: X-ray structural analysis was used to study binding of effector molecule to a prokaryotic transcription factor. NMR and SAXS techniques were used to study interaction of a monoclonal antibody with its protein antigen. Transcriptional regulator DeoR negatively regulates the expression of catabolic genes for the utilization of deoxyribonucleosides and deoxyribose in Bacillus subtilis. DeoR comprises an N-terminal DNA-binding domain and a C-terminal effector-binding domain (C-DeoR), and its function is regulated by binding of a small-molecular effector deoxyribose-5-phosphate. We determined crystal structures of C-DeoR both in the free form and in complex with deoxyribose-5-phosphate. Structural analysis revealed unique covalent binding of effector molecule through a reversible Schiff-base double bond with an effector-binding-site lysine residue. The physiological nature of this binding mode was...
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Structural study of the ASK1:thioredoxin complex.
Pšenáková, Katarína ; Obšil, Tomáš (advisor) ; Štěpánek, Miroslav (referee)
5 ABSTRACT The mitogen-activated protein kinase (MAPK) cascade is an essential member of the cell defense system against stressors. The capability and efficiency of the cell reactions to different stress signals depend on signal transduction pathway, where signals from MAPK kinase kinase (MAP3K) are transferred through phosphorylation to downstream MAPK kinase (MAP2K) and finally to MAPK. Apoptosis signal-regulating kinase 1 (ASK1) is a member of a MAP3K family and its activation and inhibition has a significant participation in a regulation of cell response to stress stimuli. The regulation of ASK1 has a strong influence in pathogenesis of several diseases, the excessive activation of human ASK1 or failure in the control of its function are associated with cardiovascular diseases, neurodegenerative disorders, inflammatory diseases, infectious diseases, tumorigenesis, asthma, diabetes and ageing. The activity of ASK1 is regulated by its interaction with several proteins, the attention is focused on two physiological inhibitors, mammalian thioredoxin (TRX) and the 14-3-3 protein. ASK1 in its inactive form is inhibited by bonds formation with TRX and 14-3-3, however the explicit mechanism of this interaction is unclear due to the absence of structural data. This work is a part of an extensive research about...
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