%0 Journal Article
%T Single-Chain Expression and Crystallization of an Antigenic C-Terminus in Complex with the Regulatory Domain of ER Aminopeptidase 1
%A Lufei Sui
%A Amit Gandhi
%A Hwai-Chen Guo
%J Crystal Structure Theory and Applications
%P 47-52
%@ 2169-2505
%D 2015
%I Scientific Research Publishing
%R 10.4236/csta.2015.44006
%X Human endoplasmic
reticulum aminopeptidase 1 (ERAP1) is one of two ER luminal aminopeptidases
that participate in the final processing of peptide precursors and generates
the N-termini of the MHC class I-restricted epitopes. In order to investigate
the interactions of its binding site with substrate peptides, X-ray
crystallographic analyses have been carried out to study structures of ERAP1
regulatory (ERAP1_R) domain in complex with antigenic peptides. Single-chain
bimodular constructs with various antigenic peptides linked to the C-terminal
end of ERAP1_R domain are designed to facilitate crystallization process of
these complexes. These recombinant proteins have been purified and crystalized,
and x-ray diffraction data of one crystal have been processed to a resolution
of 2.8 <img src=\"Edit_c89208f6-bc5f-4ada-ab0a-0754389b7d7f.bmp\" alt=\"\" />. The crystal belongs to the space group P2<sub>1</sub>, with unit cell
parameters a =64.2, b = 66.8, c = 66.3 <img src=\"Edit_b4477aa9-7491-4044-bb4d-4e429e5af6c0.bmp\" alt=\"\" />, <i>¦Â </i>= 110.2¡ã. A Refmac-refined omit map reveals a clear density for the
antigenic peptide¡¯s carboxylate-end that is in contact with the ERAP1
regulatory domain of neighboring molecule. Thus the single-chain bimodular
constructs have provided an expedited approach to study sequence-specific
interactions between the ERAP1 regulatory domain and antigen peptide¡¯s
C-terminal ends.
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%K Endoplasmic Reticulum Aminopeptidase 1 (ERAP1)
%K ERAP1 Regulatory Domain
%K Antigen  Presentation
%K X-Ray Crystallography
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=61428