Structural analysis of the Candida albicans mitochondrial DNA maintenance factor Gcf1p reveals a dynamic DNA-bridging mechanism
|Title||Structural analysis of the Candida albicans mitochondrial DNA maintenance factor Gcf1p reveals a dynamic DNA-bridging mechanism|
|Publication Type||Journal Article|
|Year of Publication||2023|
|Authors||Tarrés-Solé, Aleix, Battistini Federica, Gerhold Joachim M., Piétrement Olivier, Martínez-García Belén, Ruiz-López Elena, Lyonnais Sébastien, Bernadó Pau, Roca Joaquim, Orozco Modesto, Le Cam Eric, Sedman Juhan, and Solà Maria|
|Journal||Nucleic Acids Research|
The compaction of mitochondrial DNA (mtDNA) is regulated by architectural HMG-box proteins whose limited cross-species similarity suggests diverse underlying mechanisms. Viability of Candida albicans, a human antibiotic-resistant mucosal pathogen, is compromised by altering mtDNA regulators. Among them, there is the mtDNA maintenance factor Gcf1p, which differs in sequence and structure from its human and Saccharomyces cerevisiae counterparts, TFAM and Abf2p. Our crystallographic, biophysical, biochemical and computational analysis showed that Gcf1p forms dynamic protein/DNA multimers by a combined action of an N-terminal unstructured tail and a long helix. Furthermore, an HMG-box domain canonically binds the minor groove and dramatically bends the DNA while, unprecedentedly, a second HMG-box binds the major groove without imposing distortions. This architectural protein thus uses its multiple domains to bridge co-aligned DNA segments without altering the DNA topology, revealing a new mechanism of mtDNA condensation.
|Short Title||Nucleic Acids Research|