Sequence-specific dynamic DNA bending explains mitochondrial TFAM's dual role in DNA packaging and transcription initiation.

Autor: Huh H; Institute for Quantitative Biomedicine, Rutgers University, Piscataway, NJ, 08854, USA., Shen J; Graduate School of Biomedical Sciences, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA.; Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA., Ajjugal Y; Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA., Ramachandran A; Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA., Patel SS; Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA. patelss@rutgers.edu., Lee SH; Institute for Quantitative Biomedicine, Rutgers University, Piscataway, NJ, 08854, USA. shlee@physics.rutgers.edu.; Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, 08854, USA. shlee@physics.rutgers.edu.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2024 Jun 27; Vol. 15 (1), pp. 5446. Date of Electronic Publication: 2024 Jun 27.
DOI: 10.1038/s41467-024-49728-6
Abstrakt: Mitochondrial transcription factor A (TFAM) employs DNA bending to package mitochondrial DNA (mtDNA) into nucleoids and recruit mitochondrial RNA polymerase (POLRMT) at specific promoter sites, light strand promoter (LSP) and heavy strand promoter (HSP). Herein, we characterize the conformational dynamics of TFAM on promoter and non-promoter sequences using single-molecule fluorescence resonance energy transfer (smFRET) and single-molecule protein-induced fluorescence enhancement (smPIFE) methods. The DNA-TFAM complexes dynamically transition between partially and fully bent DNA conformational states. The bending/unbending transition rates and bending stability are DNA sequence-dependent-LSP forms the most stable fully bent complex and the non-specific sequence the least, which correlates with the lifetimes and affinities of TFAM with these DNA sequences. By quantifying the dynamic nature of the DNA-TFAM complexes, our study provides insights into how TFAM acts as a multifunctional protein through the DNA bending states to achieve sequence specificity and fidelity in mitochondrial transcription while performing mtDNA packaging.
(© 2024. The Author(s).)
Databáze: MEDLINE
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