Imagen de Portada

Dynamics and Regulation of RecA Polymerization and De-Polymerization on Double-Stranded DNA

Guardado en:
Publicado en:PLoS One vol. 8, no. 6 (Jun 2013), p. e66712
Autor principal: Fu, Hongxia
Otros Autores: Le, Shimin, Muniyappa, Kalappa, Yan, Jie
Publicado:
Public Library of Science
Materias:
Singapore
Nucleation
Polymerization
Biochemistry
DNA repair
Binding sites
Spatial discrimination
Physiological effects
RecA protein
DNA structure
Physiological factors
Competition
Substrates
Experiments
Studies
Spatial resolution
Environmental
pH effects
Deoxyribonucleic acid > DNA
Stability
Addition polymerization
Regulatory mechanisms (biology)
Elongated structure
Temperature effects
E coli
Acceso en línea:Citation/Abstract
Full Text
Full Text - PDF
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
Resumen:The RecA filament formed on double-stranded (ds) DNA is proposed to be a functional state analogous to that generated during the process of DNA strand exchange. RecA polymerization and de-polymerization on dsDNA is governed by multiple physiological factors. However, a comprehensive understanding of how these factors regulate the processes of polymerization and de-polymerization of RecA filament on dsDNA is still evolving. Here, we investigate the effects of temperature, pH, tensile force, and DNA ends (in particular ssDNA overhang) on the polymerization and de-polymerization dynamics of the E. coli RecA filament at a single-molecule level. Our results identified the optimal conditions that permitted spontaneous RecA nucleation and polymerization, as well as conditions that could maintain the stability of a preformed RecA filament. Further examination at a nano-meter spatial resolution, by stretching short DNA constructs, revealed a striking dynamic RecA polymerization and de-polymerization induced saw-tooth pattern in DNA extension fluctuation. In addition, we show that RecA does not polymerize on S-DNA, a recently identified novel base-paired elongated DNA structure that was previously proposed to be a possible binding substrate for RecA. Overall, our studies have helped to resolve several previous single-molecule studies that reported contradictory and inconsistent results on RecA nucleation, polymerization and stability. Furthermore, our findings also provide insights into the regulatory mechanisms of RecA filament formation and stability in vivo.
ISSN:1932-6203
DOI:10.1371/journal.pone.0066712
Fuente:Health & Medical Collection