5jh0
From Proteopedia
(Difference between revisions)
| Line 9: | Line 9: | ||
== Function == | == Function == | ||
[https://www.uniprot.org/uniprot/ABF2_YEAST ABF2_YEAST] Specific binding to the autonomously replicating sequence 1 (ARS1). Interaction with regulatory regions: probably involved in compacting the mitochondrial genome. It might play a positive role in gene expression and replication. | [https://www.uniprot.org/uniprot/ABF2_YEAST ABF2_YEAST] Specific binding to the autonomously replicating sequence 1 (ARS1). Interaction with regulatory regions: probably involved in compacting the mitochondrial genome. It might play a positive role in gene expression and replication. | ||
| - | <div style="background-color:#fffaf0;"> | ||
| - | == Publication Abstract from PubMed == | ||
| - | The mitochondrial genome (mtDNA) is assembled into nucleo-protein structures termed nucleoids and maintained differently compared to nuclear DNA, the involved molecular basis remaining poorly understood. In yeast (Saccharomyces cerevisiae), mtDNA is a approximately 80 kbp linear molecule and Abf2p, a double HMG-box protein, packages and maintains it. The protein binds DNA in a non-sequence-specific manner, but displays a distinct 'phased-binding' at specific DNA sequences containing poly-adenine tracts (A-tracts). We present here two crystal structures of Abf2p in complex with mtDNA-derived fragments bearing A-tracts. Each HMG-box of Abf2p induces a 90 degrees bend in the contacted DNA, causing an overall U-turn. Together with previous data, this suggests that U-turn formation is the universal mechanism underlying mtDNA compaction induced by HMG-box proteins. Combining this structural information with mutational, biophysical and computational analyses, we reveal a unique DNA binding mechanism for Abf2p where a characteristic N-terminal flag and helix are crucial for mtDNA maintenance. Additionally, we provide the molecular basis for A-tract mediated exclusion of Abf2p binding. Due to high prevalence of A-tracts in yeast mtDNA, this has critical relevance for nucleoid architecture. Therefore, an unprecedented A-tract mediated protein positioning mechanism regulates DNA packaging proteins in the mitochondria, and in combination with DNA-bending and U-turn formation, governs mtDNA compaction. | ||
| - | |||
| - | DNA structure directs positioning of the mitochondrial genome packaging protein Abf2p.,Chakraborty A, Lyonnais S, Battistini F, Hospital A, Medici G, Prohens R, Orozco M, Vilardell J, Sola M Nucleic Acids Res. 2017 Jan 25;45(2):951-967. doi: 10.1093/nar/gkw1147. Epub 2016, Nov 29. PMID:27899643<ref>PMID:27899643</ref> | ||
| - | |||
| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| - | </div> | ||
| - | <div class="pdbe-citations 5jh0" style="background-color:#fffaf0;"></div> | ||
| - | == References == | ||
| - | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
Current revision
Crystal structure of the mitochondrial DNA packaging protein Abf2p in complex with DNA at 2.18 Angstrom resolution
| |||||||||||
