title: Genetic evidence for a structural interaction between the carboxy termini of the membrane and nucleocapsid proteins of mouse hepatitis virus.
abstract: The coronavirus membrane (M) protein is the most abundant virion protein and the key component in viral assembly and morphogenesis. The M protein of mouse hepatitis virus (MHV) is an integral membrane protein with a short ectodomain, three transmembrane segments, and a large carboxy-terminal endodomain facing the interior of the viral envelope. The carboxy terminus of MHV M has previously been shown to be extremely sensitive to mutation, both in a virus-like particle expression system and in the intact virion. We have constructed a mutant, M(Delta)2, containing a two-amino-acid truncation of the M protein that was previously thought to be lethal. This mutant was isolated by means of targeted RNA recombination with a powerful host range-based selection allowed by the interspecies chimeric virus fMHV (MHV containing the ectodomain of the feline infectious peritonitis virus S protein). Analysis of multiple second-site revertants of the M(Delta)2 mutant has revealed changes in regions of both the M protein and the nucleocapsid (N) protein that can compensate for the loss of the last two residues of the M protein. Our data thus provide the first genetic evidence for a structural interaction between the carboxy termini of the M and N proteins of MHV. In addition, this work demonstrates the efficacy of targeted recombination with fMHV for the systematic genetic analysis of coronavirus structural protein interactions.
authors.affiliation: Wadsworth Center, New York State Department of Health, Albany, New York 12201-2002, USA.
authors.forename: Lili
authors.initials: L
authors.lastname: Kuo
authors.forename: Paul S
authors.initials: PS
authors.lastname: Masters
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D000086862:Coronavirus M Proteins; D008562:Membrane Glycoproteins / Q000235:genetics; D008969:Molecular Sequence Data; D006517:Murine hepatitis virus / Q000378:metabolism*; D009154:Mutation; D019251:Nucleocapsid / Q000235:genetics* / Q000378:metabolism; D019590:Nucleocapsid Proteins; D011485:Protein Binding; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins / Q000235:genetics; D014763:Viral Matrix Proteins / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication
chemical_list: D000086862:Coronavirus M Proteins; D008562:Membrane Glycoproteins; D019590:Nucleocapsid Proteins; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins; D014763:Viral Matrix Proteins; C099600:nucleocapsid protein, Hepatitis virus; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus