Sequence-specific dynamic DNA bending explains mitochondrial TFAM's dual role in DNA packaging and transcription initiation.
Nat Commun
; 15(1): 5446, 2024 Jun 27.
Article
in En
| MEDLINE
| ID: mdl-38937458
ABSTRACT
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.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Transcription Factors
/
DNA, Mitochondrial
/
Promoter Regions, Genetic
/
Mitochondrial Proteins
/
Fluorescence Resonance Energy Transfer
/
DNA Packaging
/
DNA-Binding Proteins
/
Nucleic Acid Conformation
Limits:
Humans
Language:
En
Journal:
Nat Commun
Journal subject:
BIOLOGIA
/
CIENCIA
Year:
2024
Document type:
Article
Affiliation country:
United States