Definition: In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
Input: The structural and intracellular proteins of the murine hepatitis viruses MHV-JHM and MHV-A59 were studied by tryptic peptide mapping. The results demonstrated that the virions contained three distinct proteins: the two related chains of the E2 complex, the nucleocapsid protein and the heterogeneous E1 complex. Five distinct virus-specific proteins were synthesized by infected cells. Three of the five intracellular proteins contained tryptic-peptides with properties similar to the three structural proteins. Models describing the evolution of the proteins are proposed. Although the pathogenic properties of MHV-JttM and MHV-A59 differ greatly, the tryptic peptide maps of the corresponding proteins of these MHV strMns were remarkably similar. 334 C.W. BOND, K. A~VD~,~SON, and J. L. LEIBOWITZ: at least seven virus-specific RNA species that function as mRNAs (12, 13, 20, 22) . Five of the seven mRNAs have been translated in vitro and coding assignments have been made (13, 20) . Five to nine virus-specific proteins have been identified in cells infected by MHV-JHM, MHV-A59 or MHV-3 (1, 3, 5, 18, 21) . The virus-specific proteins were identified by comparison of immunoprecipitates of infected and mock-infected cell lysates with purified virions by SDS-polyacryIamide gel electrophoresis (SDS-PAGE). STURMAN (26) proposed a model for the structure of MHV-A59. Three structural proteins were described; the nucleocapsid phosphoprotein (N), the transmembrane gtycoprotein (El) and the peplomerie glycoprotein complex (E 2), which consists of two related proteins. SIDDELL (19) analyzed the structural and intracellular proteins of MHV-JHYI by tryptic peptide mapping of ssS-methionine-labeled proteins. The results indicated that six distinct virus-specific proteins were synthesized by infected cells during the acute infection. The virus particles contained four of these proteins. WEiss and LEIBOWITZ (31) demonstrated by molecular hybridization that the genomes of MHV strains JHM and A59 are closely related in sequence. The molecular weights of the MHV-JHM and MHV-A 59 proteins are similar by SDS-PAGE (2, 3), yet the pathogenic properties of these two viruses are strikingly different (15, 17). In this communication we present tryptic peptide maps of MHV-JHM and MHV-A59 proteins.

Archives of Virology Protein Synthesis in Cells Infected by Murine Hepatitis Viruses JHM and A 59: Tryptie Peptide Analysis