Coordinating assembly of a bacterial macromolecular machine

Chevance, Fabienne F. V.; Hughes, Kelly T.

doi:10.1038/nrmicro1887

Cited by 636 publications

(734 citation statements)

References 118 publications

(152 reference statements)

Supporting

Mentioning

720

Contrasting

Unclassified

Order By: Relevance

“…On completion of HBB assembly, FlgM is secreted into the culture media, freeing σ28 and allowing it to transcribe class 3 genes responsible for filament formation, motor function, and chemotaxis (9,10). This regulatory system is well conserved among gram-negative enteric bacteria (11). Other bacteria, such as Caulobacter spp.…”

mentioning

confidence: 99%

Structural insight into the regulatory mechanisms of interactions of the flagellar type III chaperone FliT with its binding partners

Imada

Minamino

Kinoshita

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

For self-assembly of the bacterial flagellum, most of the flagellar component proteins synthesized in the cytoplasm are exported by the flagellar type III export apparatus to the growing, distal end. Flagellar protein export is highly organized and well controlled in every step of the flagellar assembly process. Flagellar-specific chaperones not only facilitate the export of their cognate proteins, as well as prevent their premature aggregation in the cytoplasm, but also play a role in finetuning flagellar gene expression to be coupled with the flagellar assembly process. FliT is a flagellar-specific chaperone responsible for the export of the filament-capping protein FliD and for negative control of flagellar gene expression by binding to the FlhDC complex. Here we report the crystal structure of Salmonella FliT at 3.2-Å resolution. The structural and biochemical analyses clearly reveal that the C-terminal segment of FliT regulates its interactions with the FlhDC complex, FliI ATPase, and FliJ (subunits of the export apparatus), and that its conformational change is responsible for the switch in its binding partners during flagellar protein export.bacterial flagellum | crystal structure | flagellar gene expression | molecular chaperone | type III protein export

show abstract

mentioning

confidence: 99%

Structural insight into the regulatory mechanisms of interactions of the flagellar type III chaperone FliT with its binding partners

Imada

Minamino

Kinoshita

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…The modeling efforts in this direction have been limited to only the FliAFlgM interaction, which has been the most well-understood interaction in the network, and is thought to be the key check-point in the process (Chevance and Hughes 2008;Chilcott and Hughes 2000;Hughes et al 1993). However, important differences exist between flagellar regulation in E. coli and Salmonella.…”

Section: Resultsmentioning

confidence: 99%

Mathematical model of flagella gene expression dynamics in Salmonella enterica serovar typhimurium

et al. 2015

View full text Add to dashboard Cite

Flagellar assembly in Salmonella is controlled by an intricate genetic and biochemical network. This network comprises of a number of inter-connected feedback loops, which control the assembly process dynamically. Critical among these are the FliA-FlgM feedback, FliZ-mediated positive feedback, and FliT-mediated negative feedback. In this work, we develop a mathematical model to track the dynamics of flagellar gene expression in Salmonella. Analysis of our model demonstrates that the network is wired to not only control the transition of the cell from a non-flagellated to a flagellated state, but to also control dynamics of gene expression during cell division. Further, we predict that FliZ encoded in the flagellar regulon acts as a critical secretion-dependent molecular link between flagella and Salmonella Pathogenicity Island 1 gene expression. Sensitivity analysis of the model demonstrates that the flagellar regulatory network architecture is extremely robust to mutations.

show abstract

“…However, it has long been known that mutants of E. coli defective in ubiquinone biosynthesis lack flagella and are immotile under aerobic conditions (Bar Tana et al, 1977). This is because reduced ability to generate the proton-motive force would compromise the energy source for flagellar biogenesis and rotation (Chevance & Hughes, 2008). In this study, strains of S. enterica were created bearing deletion mutations of the ubiA or ubiE genes to confirm that motility and flagellar biogenesis would be inhibited.…”

Section: Introductionmentioning

confidence: 99%

“…The energy from the proton motive force (Mitchell, 1979) resulting from respiratory chain activity has many functions that include the synthesis of ATP by F 1 F o ATP synthase, active transport of nutrients across the cytoplasmic membrane, export of unwanted solutes, and biogenesis and rotation of the flagellum (Chevance & Hughes, 2008). The respiratory chain comprises two classes of enzymes, dehydrogenases functioning as quinone reductases and terminal reductases functioning as quinol oxidases.…”

Section: Introductionmentioning

confidence: 99%

Randomly selected suppressor mutations in genes for NADH : quinone oxidoreductase-1, which rescue motility of a Salmonella ubiquinone-biosynthesis mutant strain

et al. 2014

View full text Add to dashboard Cite

The primary mobile electron-carrier in the aerobic respiratory chain of Salmonella is ubiquinone. Demethylmenaquinone and menaquinone are alternative electron-carriers involved in anaerobic respiration. Ubiquinone biosynthesis was disrupted in strains bearing deletions of the ubiA or ubiE genes. In soft tryptone agar both mutant strains swam poorly. However, the ubiA deletion mutant strain produced suppressor mutant strains with somewhat rescued motility and growth. Six independent suppressor mutants were purified and comparative genome sequence analysis revealed that they each bore a single new missense mutation, which localized to genes for subunits of NADH : quinone oxidoreductase-1. Four mutants bore an identical nuoG(Q297K) mutation, one mutant bore a nuoM(A254S) mutation and one mutant bore a nuoN(A444E) mutation. The NuoG subunit is part of the hydrophilic domain of NADH : quinone oxidoreductase-1 and the NuoM and NuoN subunits are part of the hydrophobic membrane-embedded domain. Respiration was rescued and the suppressed mutant strains grew better in Luria-Bertani broth medium and could use L-malate as a sole carbon source. The quinone pool of the cytoplasmic membrane was characterized by reversed-phase HPLC. Wild-type cells made ubiquinone and menaquinone. Strains with a ubiA deletion mutation made demethylmenaquinone and menaquinone and the ubiE deletion mutant strain made demethylmenaquinone and 2-octaprenyl-6-methoxy-1,4-benzoquinone; the total quinone pool was reduced. Immunoblotting found increased NADH : quinone oxidoreductase-1 levels for ubiquinone-biosynthesis mutant strains and enzyme assays measured electron transfer from NADH to demethylmenaquinone or menaquinone. Under certain growth conditions the suppressor mutations improved electron flow activity of NADH : quinone oxidoreductase-1 for cells bearing a ubiA deletion mutation.

show abstract

Coordinating assembly of a bacterial macromolecular machine

Cited by 636 publications

References 118 publications

Structural insight into the regulatory mechanisms of interactions of the flagellar type III chaperone FliT with its binding partners

Structural insight into the regulatory mechanisms of interactions of the flagellar type III chaperone FliT with its binding partners

Mathematical model of flagella gene expression dynamics in Salmonella enterica serovar typhimurium

Randomly selected suppressor mutations in genes for NADH : quinone oxidoreductase-1, which rescue motility of a Salmonella ubiquinone-biosynthesis mutant strain

Contact Info

Product

Resources

About