Crystal Structure of ERAP1 Peptide Binding Domain
[ERAP1_HUMAN] Aminopeptidase that plays a central role in peptide trimming, a step required for the generation of most HLA class I-binding peptides. Peptide trimming is essential to customize longer precursor peptides to fit them to the correct length required for presentation on MHC class I molecules. Strongly prefers substrates 9-16 residues long. Rapidly degrades 13-mer to a 9-mer and then stops. Preferentially hydrolyzes the residue Leu and peptides with a hydrophobic C-terminus, while it has weak activity toward peptides with charged C-terminus. May play a role in the inactivation of peptide hormones. May be involved in the regulation of blood pressure through the inactivation of angiotensin II and/or the generation of bradykinin in the kidney.  
Publication Abstract from PubMed
Endoplasmic reticulum aminopeptidase 1 (ERAP1) is an essential component of the immune system, because it trims peptide precursors and generates the N--restricted epitopes. To examine ERAP1's unique properties of length- and sequence-dependent processing of antigen precursors, we report a 2.3 A resolution complex structure of the ERAP1 regulatory domain. Our study reveals a binding conformation of ERAP1 to the carboxyl terminus of a peptide, and thus provides direct evidence for the molecular ruler mechanism.
Structural insights into the molecular ruler mechanism of the endoplasmic reticulum aminopeptidase ERAP1.,Gandhi A, Lakshminarasimhan D, Sun Y, Guo HC Sci Rep. 2011;1:186. Epub 2011 Dec 13. PMID:22355701
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.