Related Experiment Video

Updated: Oct 16, 2026

Generation of Null Mutants to Elucidate the Role of Bacterial Glycosyltransferases in Bacterial Motility
12:29

Generation of Null Mutants to Elucidate the Role of Bacterial Glycosyltransferases in Bacterial Motility

Published on: March 11, 2022

The G-protein FlhF has a role in polar flagellar placement and general stress response induction in Pseudomonas

S Pandza1, M Baetens, C H Park

  • 1Department of Microbiology and Immunology, Sherman Fairchild Science Building, 299 Campus Drive, Stanford University, Stanford, CA 94305, USA.

Molecular Microbiology
|May 3, 2000
PubMed

Insights

Disrupting the flhF gene in Pseudomonas putida causes random flagellar arrangement and loss of directional motility. This gene is crucial for polar flagella formation and impacts stress resistance and protein synthesis.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Bacterial Motility

Background:

  • The flhF gene in Pseudomonas putida encodes a GTP-binding protein essential for flagellar motility.
  • Wild-type P. putida exhibits polar flagella and directional motility, regulated by the flagellar-motility-chemotaxis operon.
  • The flhF gene product shows homology to the signal recognition particle (SRP) pathway receptor, suggesting a role in protein translocation.

Purpose of the Study:

  • To investigate the role of the flhF gene in flagellar arrangement, motility, and protein synthesis in Pseudomonas putida.
  • To explore the potential involvement of the SRP pathway in polar flagellar placement.

Main Methods:

  • Gene disruption and allelic replacement of the flhF gene in P. putida.
  • Analysis of flagellar arrangement and motility using microscopy and motility assays.
  • Assessment of protein synthesis patterns and starvation-induced general stress resistance (SGSR) in wild-type and mutant strains.

Main Results:

  • flhF disruption resulted in random flagellar arrangement and loss of directional motility.
  • Restoration of a functional flhF allele rescued polar flagella and motility.
  • Overexpression of flhF increased flagellar number but did not restore directional motility.
  • The flhF mutant (MK107) showed impaired starvation-induced general stress resistance (SGSR) and altered protein synthesis.

Conclusions:

  • The flhF gene is critical for establishing polar flagellar arrangement and directional motility in P. putida.
  • The SRP pathway may play a role in the polar localization of flagella.
  • flhF also influences bacterial stress resistance and protein homeostasis, indicating a broader cellular function beyond motility.

More Related Videos

Imaging G-protein Coupled Receptor (GPCR)-mediated Signaling Events that Control Chemotaxis of Dictyostelium Discoideum09:40

Imaging G-protein Coupled Receptor (GPCR)-mediated Signaling Events that Control Chemotaxis of Dictyostelium Discoideum

Published on: September 20, 2011

High-throughput Method for Observing Motility Phenotypes in Pseudomonas aeruginosa07:23

High-throughput Method for Observing Motility Phenotypes in Pseudomonas aeruginosa

Published on: June 20, 2025

Related Concept Videos

Other Stress Responses in Bacteria01:30

Other Stress Responses in Bacteria

Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...
GPCRs Regulate Adenylyl Cylase Activity01:09

GPCRs Regulate Adenylyl Cylase Activity

Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells.
Two...
Activation and Inactivation of G Proteins01:22

Activation and Inactivation of G Proteins

Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high affinity and are together...
Stringent Response in E. coli01:23

Stringent Response in E. coli

Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
G Protein-coupled Receptors01:15

G Protein-coupled Receptors

G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GTPases and their Regulation02:14

GTPases and their Regulation

Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒  small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins, also known...