PelB 319-436 from Pseudomonas aeruginosa PAO1

Experimental Data Snapshot

  • Resolution: 2.82 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.215 
  • R-Value Observed: 0.221 

wwPDB Validation   3D Report Full Report

This is version 1.3 of the entry. See complete history


PelA and PelB proteins form a modification and secretion complex essential for Pel polysaccharide-dependent biofilm formation in Pseudomonas aeruginosa.

Marmont, L.S.Whitfield, G.B.Rich, J.D.Yip, P.Giesbrecht, L.B.Stremick, C.A.Whitney, J.C.Parsek, M.R.Harrison, J.J.Howell, P.L.

(2017) J Biol Chem 292: 19411-19422

  • DOI: https://doi.org/10.1074/jbc.M117.812842
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The pellicle (PEL) polysaccharide is synthesized by the opportunistic pathogen Pseudomonas aeruginosa and is an important biofilm constituent critical for bacterial virulence and persistence. PEL is a cationic polymer that promotes cell-cell interactions within the biofilm matrix through electrostatic interactions with extracellular DNA. Translocation of PEL across the outer membrane is proposed to occur via PelB, a membrane-embedded porin with a large periplasmic domain predicted to contain 19 tetratricopeptide repeats (TPRs). TPR-containing domains are typically involved in protein-protein interactions, and we therefore sought to determine whether PelB serves as a periplasmic scaffold that recruits other components of the PEL secretion apparatus. In this study, we show that the TPR domain of PelB interacts with PelA, an enzyme with PEL deacetylase and hydrolase activities. Structure determination of PelB TPRs 8-11 enabled us to design systematic deletions of individual TPRs and revealed that repeats 9-14, which are required for the cellular localization of PelA with PelB are also essential for PEL-dependent biofilm formation. Copurification experiments indicated that the interaction between PelA and PelB is direct and that the deacetylase activity of PelA increases and its hydrolase activity decreases when these proteins interact. Combined, our results indicate that the TPR-containing domain of PelB localizes PelA to the PEL secretion apparatus within the periplasm and that this may allow for efficient deacetylation of PEL before its export from the cell.

  • Organizational Affiliation

    From the Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
PelB118Pseudomonas aeruginosa PAO1Mutation(s): 0 
Gene Names: pelBPA3063
Find proteins for Q9HZE5 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1))
Explore Q9HZE5 
Go to UniProtKB:  Q9HZE5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9HZE5
Sequence Annotations
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on MSE
Experimental Data & Validation

Experimental Data

  • Resolution: 2.82 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.215 
  • R-Value Observed: 0.221 
  • Space Group: P 65 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 61.14α = 90
b = 61.14β = 90
c = 217.75γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Canadian Institutes of Health Research (CIHR)Canada--

Revision History  (Full details and data files)

  • Version 1.0: 2017-10-04
    Type: Initial release
  • Version 1.1: 2017-10-18
    Changes: Database references
  • Version 1.2: 2017-12-13
    Changes: Database references
  • Version 1.3: 2020-01-08
    Changes: Author supporting evidence