crystal structure of Hcp2 from Salmonella typhimurium

Experimental Data Snapshot

  • Resolution: 3.00 Å
  • R-Value Free: 0.280 
  • R-Value Work: 0.237 
  • R-Value Observed: 0.239 

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Crystal structure of the putative cytoplasmic protein STM0279 (Hcp2) from Salmonella typhimurium

Lin, Q.P.Gao, Z.Q.Geng, Z.Zhang, H.Dong, Y.H.

(2017) Acta Crystallogr F Struct Biol Commun 73: 463-468

  • DOI: https://doi.org/10.1107/S2053230X17010512
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    STM0279 is a putative cytoplasmic protein from Salmonella typhimurium and was recently renamed haemolysin co-regulated protein 2 (Hcp2), with the neighbouring STM0276 being Hcp1. Both of them are encoded by the type VI secretion system (T6SS) of the Salmonella pathogenicity island 6 (SPI-6) locus and have high sequence identity. The Hcp proteins may function as a vital component of the T6SS nanotube and as a transporter and chaperone of diverse effectors from the bacterial T6SS. In this study, the crystal structure and the oligomeric state in solution of Hcp2 from S. typhimurium (StHcp2) were investigated. The crystal structure refined to 3.0 Å resolution showed that the protein is composed of a β-barrel domain with extended loops and can form hexameric rings as observed in known Hcp homologues. Mutation of the extended loop was found to partly destabilize the hexameric conformation into monomers or cause the production of inclusion bodies, suggesting it has an important role in hexameric ring formation.

  • Organizational Affiliation

    School of Life Sciences, University of Science and Technology of China, Hefei 230027, People's Republic of China.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Hcp1 family type VI secretion system effector
A, B, C, D, E
A, B, C, D, E, F
161Salmonella enterica subsp. enterica serovar TyphimuriumMutation(s): 0 
Gene Names: sciMBKC11_01435BLM41_12410DD95_17705SEETMRM10961_1365
Find proteins for H9L4J8 (Salmonella typhimurium)
Explore H9L4J8 
Go to UniProtKB:  H9L4J8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupH9L4J8
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 3.00 Å
  • R-Value Free: 0.280 
  • R-Value Work: 0.237 
  • R-Value Observed: 0.239 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 102.645α = 90
b = 147.786β = 123.74
c = 85.687γ = 90
Software Package:
Software NamePurpose
HKL-3000data reduction
HKL-3000data scaling

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number

Revision History  (Full details and data files)

  • Version 1.0: 2017-08-16
    Type: Initial release
  • Version 1.1: 2023-11-22
    Changes: Data collection, Database references, Refinement description