Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 21.21 kDa 
• Atom Count: 1647 
• Modelled Residue Count: 193 
• Deposited Residue Count: 196 
• Unique protein chains: 1

1U53

Novel X-Ray Structure of Na-ASP-2, a PR-1 protein from the nematode parasite Necator americanus and a vaccine antigen for human hookworm infection

• PDB DOI: 10.2210/pdb1U53/pdb

• Classification: ANTIBIOTIC
• Organism(s): Necator americanus
• Expression System: Komagataella pastoris
• Mutation(s): No 


• Deposited: 2004-07-26 Released: 2005-02-01 
• Deposition Author(s): Asojo, O.A., Goud, G., Dhar, K., Loukas, A., Zhan, B., Deumic, V., Liu, S., Borgstahl, G.E.O., Hotez, P.J.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.56 Å
• R-Value Free: 0.224 
• R-Value Work: 0.175 
• R-Value Observed: 0.178 

Literature

X-ray structure of Na-ASP-2, a pathogenesis-related-1 protein from the nematode parasite, Necator americanus, and a vaccine antigen for human hookworm infection.

Asojo, O.A., Goud, G., Dhar, K., Loukas, A., Zhan, B., Deumic, V., Liu, S., Borgstahl, G.E., Hotez, P.J.

(2005) J Mol Biol 346: 801-814

• PubMed: 15713464 
• DOI: 10.1016/j.jmb.2004.12.023
• Primary Citation of Related Structures:  
  1U53


• PubMed Abstract: 
  

Human hookworm infection is a major cause of anemia and malnutrition of adults and children in the developing world. As part of on-going efforts to control hookworm infection, The Human Hookworm Vaccine Initiative has identified candidate vaccine antigens from the infective L3 larval stages of the parasite, including a family of pathogenesis-related (PR) proteins known as the Ancylostoma-secreted proteins (ASPs). A novel crystal structure of Na-ASP-2, a PR-1 protein secreted by infective larvae of the human hookworm Necator americanus, has been solved to resolution limits of 1.68 A and to an R-factor of 17% using the recombinant protein expressed in and secreted by Pichia pastoris. The overall fold of Na-ASP-2 is a three-layer alphabetaalpha sandwich flanked by an N-terminal loop and a short, cysteine-rich C terminus. Our structure reveals a large central cavity that is flanked by His129 and Glu106, two residues that are well conserved in all parasitic nematode L3 ASPs. Na-ASP-2 has structural and charge similarities to chemokines, which suggests that Na-ASP-2 may be an extra-cellular ligand of an unknown receptor. Na-ASP-2 is a useful homology model for NIF, a natural antagonistic ligand of CR3 receptor. From these modeling studies, possible binding modes were predicted. In addition, this first structure of a PR-1 protein from parasitic helminths may shed light on the molecular basis of host-parasite interactions.

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Organizational Affiliation: 

Eppley Institute for Research in Cancer and Allied Diseases, 987696 Nebraska Medical Center, Omaha, NE 68198-7696, USA. [e-mail]

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
secreted protein ASP-2	A	196	Necator americanus	Mutation(s): 0  Gene Names: ASP2
UniProt
Find proteins for Q7Z1H1 (Necator americanus) Explore Q7Z1H1  Go to UniProtKB:  Q7Z1H1

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.56 Å
• R-Value Free: 0.224 
• R-Value Work: 0.175 
• R-Value Observed: 0.178 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 37.89	α = 90
b = 51.54	β = 114.06
c = 43.63	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
AMoRE	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2004-07-26 
• Released Date: 2005-02-01 
Deposition Author(s): Asojo, O.A., Goud, G., Dhar, K., Loukas, A., Zhan, B., Deumic, V., Liu, S., Borgstahl, G.E.O., Hotez, P.J.

Revision History  

• Version 1.0: 2005-02-01
  Type: Initial release
  
• Version 1.1: 2008-04-30
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2017-10-11
  Changes: Refinement description