4giz | pdb_00004giz
Crystal structure of full-length human papillomavirus oncoprotein E6 in complex with LXXLL peptide of ubiquitin ligase E6AP at 2.55 A resolution
Structural highlights
DiseaseUBE3A_HUMAN Defects in UBE3A are a cause of Angelman syndrome (AS) [MIM:105830; also known as 'happy puppet syndrome'. AS is characterized by features of severe motor and intellectual retardation, microcephaly, ataxia, frequent jerky limb movements and flapping of the arms and hands, hypotonia, hyperactivity, hypopigmentation, seizures, absence of speech, frequent smiling and episodes of paroxysmal laughter, and an unusual facies characterized by macrostomia, a large mandible and open-mouthed expression, a great propensity for protruding the tongue ('tongue thrusting'), and an occipital groove.[1] [2] FunctionMALE_ECOLI Involved in the high-affinity maltose membrane transport system MalEFGK. Initial receptor for the active transport of and chemotaxis toward maltooligosaccharides.UBE3A_HUMAN E3 ubiquitin-protein ligase which accepts ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and transfers it to its substrates. Several substrates have been identified including the RAD23A and RAD23B, MCM7 (which is involved in DNA replication), annexin A1, the PML tumor suppressor, and the cell cycle regulator CDKN1B. Catalyzes the high-risk human papilloma virus E6-mediated ubiquitination of p53/TP53, contributing to the neoplastic progression of cells infected by these viruses. Additionally, may function as a cellular quality control ubiquitin ligase by helping the degradation of the cytoplasmic misfolded proteins. Finally, UBE3A also promotes its own degradation in vivo.[3] [4] [5] [6] [7] [8] Publication Abstract from PubMedE6 viral oncoproteins are key players in epithelial tumors induced by papillomaviruses in vertebrates, including cervical cancer in humans. E6 proteins target many host proteins by specifically interacting with acidic LxxLL motifs. We solved the crystal structures of bovine (BPV1) and human (HPV16) papillomavirus E6 proteins bound to LxxLL peptides from the focal adhesion protein paxillin and the ubiquitin ligase E6AP, respectively. In both E6 proteins, two zinc domains and a linker helix form a basic-hydrophobic pocket, which captures helical LxxLL motifs in a way compatible with other interaction modes. Mutational inactivation of the LxxLL binding pocket disrupts the oncogenic activities of both E6 proteins. This work reveals the structural basis of both the multifunctionality and the oncogenicity of E6 proteins. Structural basis for hijacking of cellular LxxLL motifs by papillomavirus E6 oncoproteins.,Zanier K, Charbonnier S, Sidi AO, McEwen AG, Ferrario MG, Poussin-Courmontagne P, Cura V, Brimer N, Babah KO, Ansari T, Muller I, Stote RH, Cavarelli J, Vande Pol S, Trave G Science. 2013 Feb 8;339(6120):694-8. doi: 10.1126/science.1229934. PMID:23393263[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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