The Molecular Mechanism of Cellular Attachment for an Archaeal Virus

Ross Hartman; Brian J Eilers; Daniel Bollschweiler; Jacob H Munson-McGee; Harald Engelhardt; Mark J Young; C Martin Lawrence

doi:10.1016/j.str.2019.09.005

The Molecular Mechanism of Cellular Attachment for an Archaeal Virus

Structure. 2019 Nov 5;27(11):1634-1646.e3. doi: 10.1016/j.str.2019.09.005. Epub 2019 Oct 3.

Authors

Ross Hartman¹, Brian J Eilers¹, Daniel Bollschweiler², Jacob H Munson-McGee³, Harald Engelhardt², Mark J Young⁴, C Martin Lawrence⁵

Affiliations

¹ Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA.
² Department of Molecular Structural Biology, Max-Planck-Institute for Biochemistry, Martinsried, Germany.
³ Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA.
⁴ Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA; Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717, USA; The Thermal Biology Institute, Montana State University, Bozeman, MT 59717, USA. Electronic address: myoung@montana.edu.
⁵ Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA; The Thermal Biology Institute, Montana State University, Bozeman, MT 59717, USA. Electronic address: lawrence@montana.edu.

PMID: 31587916
DOI: 10.1016/j.str.2019.09.005

Abstract

Sulfolobus turreted icosahedral virus (STIV) is a model archaeal virus and member of the PRD1-adenovirus lineage. Although STIV employs pyramidal lysis structures to exit the host, knowledge of the viral entry process is lacking. We therefore initiated studies on STIV attachment and entry. Negative stain and cryoelectron micrographs showed virion attachment to pili-like structures emanating from the Sulfolobus host. Tomographic reconstruction and sub-tomogram averaging revealed pili recognition by the STIV C381 turret protein. Specifically, the triple jelly roll structure of C381 determined by X-ray crystallography shows that pilus recognition is mediated by conserved surface residues in the second and third domains. In addition, the STIV petal protein (C557), when present, occludes the pili binding site, suggesting that it functions as a maturation protein. Combined, these results demonstrate a role for the namesake STIV turrets in initial cellular attachment and provide the first molecular model for viral attachment in the archaeal domain of life.

Keywords: C381; STIV; X-ray crystallography; archaea; cryo-EM; jelly roll; pili; tomography; virus.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Archaeal Viruses / chemistry*
Archaeal Viruses / pathogenicity
Archaeal Viruses / ultrastructure
Protein Domains
Sulfolobus / virology
Viral Proteins / chemistry*
Viral Proteins / metabolism
Virus Attachment*

Substances

Viral Proteins