Related Experiment Video

Updated: Sep 18, 2025

Determination of Plasma Membrane Partitioning for Peripherally-associated Proteins
11:11

Determination of Plasma Membrane Partitioning for Peripherally-associated Proteins

Published on: June 15, 2018

8.5K

Mutational analysis of the F plasmid partitioning protein ParA reveals residues required for oligomerization and

Nivedita Mitra1,2, Dipika Mishra1,2, Manasi Mudaliyar3,4

  • 1School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, 752050, India.

Nucleic Acids Research
|June 26, 2025
PubMed

Insights

ParA proteins are key for plasmid maintenance and antimicrobial resistance. This study reveals how ParA polymerization, essential for plasmid partitioning, is regulated by ATP and specific residues, offering new antibiotic targets.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • Mobile genetic elements like plasmids are significant drivers of antimicrobial resistance.
  • Plasmid maintenance proteins, such as ParA, are potential targets for novel antibiotics.
  • ParA function in plasmid partitioning involves ATP-dependent dimerization and gradient formation, but the role of polymerization is unclear.

Purpose of the Study:

  • To investigate the role of ParA polymerization in plasmid maintenance.
  • To elucidate the mechanism of ParA polymerization and its regulation.
  • To identify key residues involved in ParA filament assembly and function.

Main Methods:

  • Site-directed mutagenesis of ParA from the F plasmid (ParAF).
  • Analysis of filament formation, DNA binding, and transcriptional repression.
  • Structural prediction and mutational analysis of filament interfaces.

Main Results:

  • Mutations Q351H and W362E in ParAF induce filament formation independent of the partitioning complex.
  • These polymerization-defective variants fail to partition plasmids and exhibit super-repression of the ParAF promoter.
  • ATP-dependent conformational changes regulate ParAF polymerization, with specific residues (R320, E375) crucial for filament assembly and plasmid partitioning.

Conclusions:

  • ParA polymerization is essential for plasmid maintenance.
  • The C-terminal helix of ParAF plays a critical role in filament assembly and plasmid partitioning.
  • Understanding ParA polymerization mechanisms can guide the development of new antimicrobial strategies targeting plasmid maintenance.

More Related Videos

Quantification of Plasmid-Mediated Antibiotic Resistance in an Experimental Evolution Approach12:32

Quantification of Plasmid-Mediated Antibiotic Resistance in an Experimental Evolution Approach

Published on: December 14, 2019

14.1K
Plasmid Stability Analysis with Open-Source Droplet Microfluidics07:43

Plasmid Stability Analysis with Open-Source Droplet Microfluidics

Published on: December 27, 2024

693

Related Concept Videos

Plasmids01:28

Plasmids

Plasmids are extrachromosomal DNA molecules found in bacteria, archaea, and some eukaryotic microbes like yeast. These small, circular DNA structures typically contain fewer than 30 genes, although some may exist linearly. Plasmids vary in their number within a cell, known as copy number. Single-copy plasmids are present in one copy per cell and multi-copy plasmids are present in multiple copies, reaching over 100 copies per cell.Plasmids usually replicate independently of the chromosomal DNA...
152
Cytoskeletal Proteins in Bacteria01:29

Cytoskeletal Proteins in Bacteria

Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
3.5K
Conservative Site-specific Recombination and Phase Variation02:53

Conservative Site-specific Recombination and Phase Variation

Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
6.1K
Conjugation01:19

Conjugation

Conjugation is a form of horizontal gene transfer that primarily occurs in bacteria and some archaea, promoting genetic diversity and adaptation. Bacteria can acquire resistance genes through conjugative plasmids, allowing them to survive antibiotic treatments that would otherwise be lethal. This process involves direct contact between cells through specialized structures such as the sex pilus and is mediated by conjugative plasmids, including the F (fertility) factor.Conjugation requires...
99
Protein Complexes with Interchangeable Parts01:57

Protein Complexes with Interchangeable Parts

Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...
2.6K