Mechanism of DNA flexibility enhancement by HMGB proteins
| Autor: | Mark C. Williams, Micah J. McCauley, N. E. Israeloff, L. James Maher, Jingyun Zhang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
Flexibility (anatomy)
HU Protein Hinge Plasma protein binding Microscopy Atomic Force HMGB2 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine HMGB Proteins Genetics medicine HMGB2 Protein HMGB1 Protein Molecular Biology 030304 developmental biology Persistence length 0303 health sciences biology DNA Molecular biology medicine.anatomical_structure High-mobility group chemistry biology.protein Biophysics Nucleic Acid Conformation 030217 neurology & neurosurgery |
| Zdroj: | Nucleic Acids Research |
| ISSN: | 1362-4962 0305-1048 |
| Popis: | The mechanism by which sequence non-specific DNA-binding proteins enhance DNA flexibility is studied by examining complexes of double-stranded DNA with the high mobility group type B proteins HMGB2 (Box A) and HMGB1 (Box A+B) using atomic force microscopy. DNA end-to-end distances and local DNA bend angle distributions are analyzed for protein complexes deposited on a mica surface. For HMGB2 (Box A) binding we find a mean induced DNA bend angle of 78 degrees, with a standard error of 1.3 degrees and a SD of 23 degrees, while HMGB1 (Box A+B) binding gives a mean bend angle of 67 degrees, with a standard error of 1.3 degrees and a SD of 21 degrees. These results are consistent with analysis of the observed global persistence length changes derived from end-to-end distance measurements, and with results of DNA-stretching experiments. The moderately broad distributions of bend angles induced by both proteins are inconsistent with either a static kink model, or a purely flexible hinge model for DNA distortion by protein binding. Therefore, the mechanism by which HMGB proteins enhance the flexibility of DNA must differ from that of the Escherichia coli HU protein, which in previous studies showed a flat angle distribution consistent with a flexible hinge model. |
| Databáze: | OpenAIRE |
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