RT Journal Article
SR Electronic
T1 Structural dynamics of E6AP E3 ligase HECT domain and involvement of flexible hinge loop in ubiquitin chain synthesis mechanism
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.11.18.516873
DO 10.1101/2022.11.18.516873
A1 Takeda, Kazusa
A1 Muro, Ikumi
A1 Kobayashi, Fuminori
A1 Flechsig, Holger
A1 Kodera, Noriyuki
A1 Ando, Toshio
A1 Konno, Hiroki
YR 2022
UL http://biorxiv.org/content/early/2022/11/18/2022.11.18.516873.abstract
AB Ubiquitin (Ub) ligases E3 are an important factor in selecting target proteins for ubiquitination and determining the type of polyubiquitin chains on the target proteins. In the HECT (homologous to E6AP C-terminus)-type E3 ligases, the HECT domain is composed of an N-lobe containing the E2-binding site and a C-lobe containing the catalytic Cys residue that forms a thioester bond with Ub. These two lobes are connected by a flexible hinge loop. The large conformational rearrangement of the HECT domain via the flexible hinge loop is essential for HECT-type E3-mediated Ub transfer from E2 to a target protein. However, detailed insights into the structural dynamics of this type of E3 ligases remain unclear. Here, we provide the first direct demonstration of structural dynamics of the E6AP HECT domain using high-speed atomic force microscopy. We also investigated structural dynamics of hinge loop flexibility restricted HECT domain, and we found that flexibility of the E6AP hinge loop has a great impact not only on its structural dynamics but also on the formation of free Ub chains mediated by E3-E3 interactions.Competing Interest StatementThe authors have declared no competing interest.