The ICP27 Homology Domain of the Human Cytomegalovirus Protein UL69 Adopts a Dimer-of-Dimers Structure.

Autor:	Tunnicliffe RB; Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom.; School of Chemistry, Faculty of Science and Engineering, The University of Manchester, Manchester, United Kingdom., Collins RF; Electron Microscopy Facility, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom., Ruiz Nivia HD; Biomolecular Analysis Core Facility, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom., Sandri-Goldin RM; Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, California, USA., Golovanov AP; Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom a.golovanov@manchester.ac.uk.; School of Chemistry, Faculty of Science and Engineering, The University of Manchester, Manchester, United Kingdom.
Jazyk:	angličtina
Zdroj:	MBio [mBio] 2018 Jun 19; Vol. 9 (3). Date of Electronic Publication: 2018 Jun 19.
DOI:	10.1128/mBio.01112-18
Abstrakt:	The UL69 protein from human cytomegalovirus (HCMV) is a multifunctional regulatory protein and a member of the ICP27 protein family conserved throughout herpesviruses. UL69 plays many roles during productive infection, including the regulation of viral gene expression, nuclear export of intronless viral RNAs, and control of host cell cycle progression. Throughout the ICP27 protein family, an ability to self-associate is correlated with the functions of these proteins in transactivating certain viral genes. Here, we determined the domain boundaries of a globular ICP27 homology domain of UL69, which mediates self-association, and characterized the oligomeric state of the isolated domain. Size exclusion chromatography coupled with multiangle light scattering (SEC-MALS) revealed that residues 200 to 540 form a stable homo-tetramer, whereas a shorter region comprising residues 248 to 536 forms a homo-dimer. Structural analysis of the UL69 tetramer by transmission electron microscopy (TEM) revealed a dimer-of-dimers three-dimensional envelope with bridge features likely from a region of the protein unique to betaherpesviruses. The data provide a structural template for tetramerization and improve our understanding of the structural diversity and features necessary for self-association within UL69 and the ICP27 family. IMPORTANCE Human cytomegalovirus (HCMV) infection is widespread in the human population but typically remains dormant in an asymptomatic latent state. HCMV causes disease in neonates and adults with suppressed or impaired immune function, as the virus is activated into a lytic state. All species of herpesvirus express a protein from the ICP27 family which functions as a posttranscriptional activator in the lytic state. In HCMV, this protein is called UL69. The region of sequence conservation in the ICP27 family is a folded domain that mediates protein interactions, including self-association and functions in transactivation. All members thus far analyzed homo-dimerize, with the exception of UL69, which forms higher-order oligomers. Here, we use biochemical and structural data to reveal that UL69 forms stable tetramers composed of a dimer of dimers and determine a region essential for cross-dimer stabilization. (Copyright © 2018 Tunnicliffe et al.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu