Crystal structure of adenovirus E3-19K bound to HLA-A2 reveals mechanism for immunomodulation.

ABSTRACT: E3-19K binds to and retains MHC class I molecules in the endoplasmic reticulum, suppressing anti-adenovirus activities of T cells. We determined the structure of the adenovirus serotype 2 (Ad2, species C) E3-19K-HLA-A2 complex to 1.95-Å resolution. Ad2 E3-19K binds to the N terminus of the HLA-A2 groove, contacting the ?1, ?2 and ?3 domains and ?(2)m. Ad2 E3-19K has a unique structure comprising a large N-terminal domain, formed by two partially overlapping ?-sheets arranged in a V shape, and a C-terminal ?-helix and tail. The structure reveals determinants in E3-19K and HLA-A2 that are important for complex formation; conservation of some of these determinants in E3-19K proteins of different species and MHC I molecules of different loci suggests a universal binding mode for all E3-19K proteins. Our structure is important for understanding the immunomodulatory function of E3-19K.

SUBMITTER: Li L 

PROVIDER: S-EPMC3492506 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature