Crystal structure of Extracellular Domain 1 (ECD1) of FtsX from S. pneumonie in complex with n-decyl-B-D-maltoside

Experimental Data Snapshot

  • Resolution: 2.16 Å
  • R-Value Free: 0.316 
  • R-Value Work: 0.260 
  • R-Value Observed: 0.263 

Starting Model: experimental
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Structure of the Large Extracellular Loop of FtsX and Its Interaction with the Essential Peptidoglycan Hydrolase PcsB in Streptococcus pneumoniae.

Rued, B.E.Alcorlo, M.Edmonds, K.A.Martinez-Caballero, S.Straume, D.Fu, Y.Bruce, K.E.Wu, H.Havarstein, L.S.Hermoso, J.A.Winkler, M.E.Giedroc, D.P.

(2019) mBio 10

  • DOI: https://doi.org/10.1128/mBio.02622-18
  • Primary Citation of Related Structures:  
    6HE6, 6HEE, 6HFX, 6MK7

  • PubMed Abstract: 

    Streptococcus pneumoniae is a leading killer of infants and immunocompromised adults and has become increasingly resistant to major antibiotics. Therefore, the development of new antibiotic strategies is desperately needed. Targeting bacterial cell division is one such strategy, specifically by targeting proteins that are essential for the synthesis and breakdown of peptidoglycan. One complex important to this process is FtsEX. FtsEX comprises a cell division-regulating integral membrane protein (FtsX) and a cytoplasmic ATPase (FtsE) that resembles an ATP-binding cassette (ABC) transporter. Here, we present nuclear magnetic resonance (NMR) solution structural and crystallographic models of the large extracellular domain of FtsX, denoted extracellular loop 1 (ECL1). The structure of ECL1 reveals an upper extended β-hairpin and a lower α-helical lobe, each extending from a mixed α-β core. The helical lobe mediates a physical interaction with the peptidoglycan hydrolase PcsB via the coiled-coil domain of PcsB (PscB CC ). Characterization of S. pneumoniae strain D39-derived strains harboring mutations in the α-helical lobe shows that this subdomain is essential for cell viability and required for proper cell division of S. pneumoniae IMPORTANCE FtsX is a ubiquitous bacterial integral membrane protein involved in cell division that regulates the activity of peptidoglycan (PG) hydrolases. FtsX is representative of a large group of ABC3 superfamily proteins that function as "mechanotransmitters," proteins that relay signals from the inside to the outside of the cell. Here, we present a structural characterization of the large extracellular loop, ECL1, of FtsX from the opportunistic human pathogen S. pneumoniae We show the molecular nature of the direct interaction between the peptidoglycan hydrolase PcsB and FtsX and demonstrate that this interaction is essential for cell viability. As such, FtsX represents an attractive, conserved target for the development of new classes of antibiotics.

  • Organizational Affiliation

    Department of Biology, Indiana University Bloomington, Bloomington, Indiana, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Cell division protein FtsXA [auth B],
B [auth A]
114Streptococcus pneumoniaeMutation(s): 0 
Gene Names: ERS044004_00806
Find proteins for Q04LE4 (Streptococcus pneumoniae serotype 2 (strain D39 / NCTC 7466))
Explore Q04LE4 
Go to UniProtKB:  Q04LE4
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ04LE4
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on DMU

Download Ideal Coordinates CCD File 
C22 H42 O11
Experimental Data & Validation

Experimental Data

  • Resolution: 2.16 Å
  • R-Value Free: 0.316 
  • R-Value Work: 0.260 
  • R-Value Observed: 0.263 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 75.496α = 90
b = 75.496β = 90
c = 95.311γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
Aimlessdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Spanish Ministry of Economy and CompetitivenessSpainBFU2017-90030-P

Revision History  (Full details and data files)

  • Version 1.0: 2019-04-24
    Type: Initial release
  • Version 1.1: 2024-01-17
    Changes: Data collection, Database references, Refinement description