Premium
Structure and functional interactions of the Tsg101 UEV domain
Author(s) -
Pornillos Owen,
Alam Steven L.,
Rich Rebecca L.,
Myszka David G.,
Davis Darrell R.,
Sundquist Wesley I.
Publication year - 2002
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/21.10.2397
Subject(s) - tsg101 , biology , ubiquitin , escrt , biochemistry , plasma protein binding , ubiquitin protein ligases , microbiology and biotechnology , ubiquitin ligase , endosome , gene , microrna , microvesicles , intracellular
Human Tsg101 plays key roles in HIV budding and in cellular vacuolar protein sorting (VPS). In performing these functions, Tsg101 binds both ubiquitin (Ub) and the PTAP tetrapeptide ‘late domain’ motif located within the viral Gag protein. These interactions are mediated by the N‐terminal domain of Tsg101, which belongs to the catalytically inactive ubiquitin E2 variant (UEV) family. We now report the struc ture of Tsg101 UEV and chemical shift mapping of the Ub and PTAP binding sites. Tsg101 UEV resembles canonical E2 ubiquitin conjugating enzymes, but has an additional N‐terminal helix, an extended β‐hairpin that links strands 1 and 2, and lacks the two C‐terminal helices normally found in E2 enzymes. PTAP‐containing peptides bind in a hydrophobic cleft exposed by the absence of the C‐terminal helices, whereas ubiquitin binds in a novel site surrounding the β‐hairpin. These studies provide a structural framework for understanding how Tsg101 mediates the protein–protein interactions required for HIV budding and VPS.