PMID: 15642263 , Related PDB id: 1XAK

Authors:

Nelson CA, Pekosz A, Lee CA, Diamond MS, Fremont DH

Title:

Structure and intracellular targeting of the SARS-coronavirus Orf7a accessory protein.

Journal:

Structure. 2005 Jan;13(1):75-85.

Abstract:

The open reading frame (ORF) 7a of the SARS-associated coronavirus (SARS-CoV) encodes a unique type I transmembrane protein of unknown function. We have determined the 1.8 A resolution crystal structure of the N-terminal ectodomain of orf7a, revealing a compact seven-stranded beta sandwich unexpectedly similar in fold and topology to members of the Ig superfamily. We also demonstrate that, in SARS-CoV- infected cells, the orf7a protein is expressed and retained intracellularly. Confocal microscopy studies using orf7a and orf7a/CD4 chimeras implicate the short cytoplasmic tail and transmembrane domain in trafficking of the protein within the endoplasmic reticulum and Golgi network. Taken together, our findings provide a structural and cellular framework in which to explore the role of orf7a in SARS-CoV pathogenesis.