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Atomic Force Microscopy (AFM)
- STRUCTURAL BIOLOGY
Contact: Dr. Volker Walhorn |
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Structural information of individual functional
molecules and complexes can be investigated by in-situ atomic
force microscopy by immobilising the biomolecules of interest
(nucleic acids, proteins, carbohydrates, …) via physical,
chemical or biological interaction on a flat surface or directly
embedded in the cellular membrane environment. The interesting
structural information includes sub-nm-conformation, molecular
symmetry, binding location and molecular temporal dynamics.
The following typical examples are recent results of actual
research projects where biological processes of a hierarchic
degree of higher complexity (transcription regulation,molecular
motors, self-assembly of 2D-protein s-layers) are investigated.
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Images: (1) DNA-protein complex, (2-3) V-ATPase
(2), (4-5) Bacterial S-layer |
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Project 1 |
Specific DNA-Protein Interaction (Transcription
Regulation) |
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Temporal dynamics of a specific binding/unbinding
event of a transcriptional activator (ExpG) which (un)binds
specifically to/from the end of an elongated DNA binding sequence
of the gene cluster of S. meliloti |
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Publications: [see section "Publications"] |
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Collaboration: A. Becker, A. Pühler,
Dept. of Genetics, Bielefeld University |
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Project 2 |
Membrane-Bound V-ATPase (Molecular Motor) |
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Membrane bound proton pumps (V-ATPase) are
functionally immobilized on a mica surface and imaged by in-situ
AFM. The ambitious aims of this research project include the
structural verification of the functional re-assembly of this
multi-heterodomain protein system, as well as the direct and
in-situ prove of the assumed rotary motion of this motor protein
(similarly to the F0F1-ATP-Synthase). |
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Publications: [see section "Publications"] |
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Collaboration: D. Golldack, K.-J. Dietz, Dept.
of Plant Physiology, Bielefeld University |
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Project 3 |
2D-Protein Surface-Layer Arrays (Protein
Self-Assembly) |
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Isolated and purified bacterial S-layers of
28 bacterial strains (Corynebacterum glutamicum) were
investigated under functional conditions with respect of molecular
structure and symmetry of the unit cell and compared to the
known genetic sequence information. This allowed a coherent
description of the investigated strains into 5 phylogenetic
subclasses and an allocation of protein structure (phenotype)
with its genetic information (genotype). Furthermore, first
experiments were successful where these self-assembled protein
arrays could be directly investigated and resolved on a immobilized
living bacterium (see section ). |
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Publications: [see section "Publications"] |
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Collaboration: N. Hansmeier, J. Kalinowski,
Dept. of Genetics, Bielefeld University |
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other ongoing projects [...] |
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We acknowledge funding from DFG within
SFB 613 (Germany) |
