5B3D

Structure of a flagellar type III secretion chaperone, FlgN

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.207 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history. 

Literature

Rearrangements of alpha-helical structures of FlgN chaperone control the binding affinity for its cognate substrates during flagellar type III export

Kinoshita, M., Nakanishi, Y., Furukawa, Y., Namba, K., Imada, K., Minamino, T.

(2016) Mol.Microbiol. 101: 656-670

  • DOI: 10.1111/mmi.13415

  • PubMed Abstract: 

    • The bacterial flagellar type III export chaperones not only act as bodyguards to protect their cognate substrates from aggregation and proteolysis in the cytoplasm but also ensure the order of export through their interactions with an export gate pro ...

    The bacterial flagellar type III export chaperones not only act as bodyguards to protect their cognate substrates from aggregation and proteolysis in the cytoplasm but also ensure the order of export through their interactions with an export gate protein FlhA. FlgN chaperone binds to FlgK and FlgL with nanomolar affinity and transfers them to FlhA for their efficient and rapid transport for the formation of the hook-filament junction zone. However, it remains unknown how FlgN releases FlgK and FlgL at the FlhA export gate platform in a timely manner. Here, we have solved the crystal structure of Salmonella FlgN at 2.3 Å resolution and carried out structure-based functional analyses. FlgN consists of three α helices, α1, α2 and α3. Helix α1 adopts two distinct, extended and bent conformations through the conformational change of N-loop between α1 and α2. The N-loop deletion not only increases the probability of FlgN dimer formation but also abolish the interaction between FlgN and FlgK. Highly conserved Asn-92, Asn-95 and Ile-103 residues in helix α3 are involved in the strong interaction with FlgK. We propose that the N-loop coordinates helical rearrangements of FlgN with the association and dissociation of its cognate substrates during their export.

    Organizational Affiliation: 

    Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Flagella synthesis protein FlgN
A, B, C, D
140Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)Mutation(s): 0 
Gene Names: flgN
Find proteins for P0A1J7 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  P0A1J7
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B, C, D
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.207 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 83.551α = 90.00
b = 91.608β = 90.00
c = 94.840γ = 90.00
Software Package:
Software NamePurpose
MOSFLMdata reduction
PHENIXrefinement
SCALAdata scaling
PHENIXphasing

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Japan Society for the Promotion of ScienceJapan15H02386
Japan Society for the Promotion of ScienceJapan26293097
Japan Society for the Promotion of ScienceJapan25000013
MEXTJapan23115008
MEXTJapan24117004
MEXTJapan25121718
MEXTJapan15H01640

Revision History 

  • Version 1.0: 2016-06-01
    Type: Initial release
  • Version 1.1: 2016-09-07
    Type: Database references