Structure of Haemophylus influenzae Universal Stress Protein At 1.85A Resolution

Experimental Data Snapshot

  • Resolution: 1.85 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.220 

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Structure of the universal stress protein of Haemophilus influenzae.

Sousa, M.C.McKay, D.B.

(2001) Structure 9: 1135-1141

  • DOI: https://doi.org/10.1016/s0969-2126(01)00680-3
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The universal stress protein UspA is a small cytoplasmic bacterial protein whose expression is enhanced several-fold when cellular viability is challenged with heat shock, nutrient starvation, stress agents which arrest cell growth, or DNA-damaging agents. UspA enhances the rate of cell survival during prolonged exposure to such conditions, suggesting that it asserts a general "stress endurance" activity. However, neither the structure of UspA nor the biochemical mechanism by which it protects cells from the broad spectrum of stress agents is known. The crystal structure of Haemophilus influenzae UspA reveals an asymmetric dimer with a tertiary alpha/beta fold similar to that of the Methanococcus jannaschi MJ0577 protein, a protein whose crystal structure revealed a novel ATP binding motif. UspA differs significantly from the MJ0577 structure in several details, including the triphosphate binding loop of the ATP binding motif; UspA shows no ATP binding activity. Within the universal stress protein family that is delineated by sequence similarity, UspA is the only member which has been correlated with a cellular activity, and MJ0577 is the only member which has been assigned a biochemical activity, i.e., ATP binding. UspA has a similar fold to the MJ0577 protein but does not bind ATP. This suggests that members of this protein family will segregate into two groups, based on whether or not they bind ATP. By implication, one subset of the universal stress proteins presumably has an ATP-dependent function, while another subset functions in ATP-independent activities.

  • Organizational Affiliation

    Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Universal Stress Protein A
A, B, C, D
141Haemophilus influenzaeMutation(s): 0 
Gene Names: USPA
Find proteins for P44880 (Haemophilus influenzae (strain ATCC 51907 / DSM 11121 / KW20 / Rd))
Explore P44880 
Go to UniProtKB:  P44880
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP44880
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.85 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.220 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 64.129α = 90
b = 63.214β = 90
c = 136.959γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-12-12
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2024-02-07
    Changes: Data collection, Database references, Derived calculations