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.

Example input: The severe acute respiratory syndrome (SARS) epidemic originating from China in 2002 was caused by a previously uncharacterized coronavirus that could be identified by specific RT-PCR amplification. Efforts to control future SARS outbreaks depend on the accurate and early identification of SARS-CoV infected patients. A real-time fluorogenic RT-PCR assay based on the 3 -noncoding region (3 -NCR) of SARS-CoV genome was developed as a quantitative SARS diagnostic tool. The ideal amplification efficiency of a sensitive SARS-CoV RT-PCR assay should yield an E value (PCR product concentration increase per amplification cycle) equal to 2.0. It was demonstrated that the 3 -NCR SARS-CoV based RT-PCR reactions could be formulated to reach excellent E values of 1.81, or 91% amplification efficacy. The SARS-CoV cDNA preparations derived from viral RNA extract and the cloned recombinant plasmid both exhibit the identical amplification characteristics, i.e. amplification efficacy using the same PCR formulation developed in this study. The viral genomic copy (or genomic equivalences, GE) per infectious unit (GE/pfu) of SARS-CoV used in this study was also established to be approximate 1200-1600:1. The assay's detection sensitivity could reach 0.005 pfu or 6-8 GE per assay. It was preliminarily demonstrated that the assay could efficiently detect SARS-CoV from clinical specimens of SARS probable and suspected patients identified in Taiwan. The 3 -NCR based SARS-CoV assay demonstrated 100% diagnostic specificity testing samples of patients with acute respiratory disease from a non-SARS epidemic region.
Example output: Development and evaluation of an efficient 3 -noncoding region-based SARS coronavirus (SARS-CoV) RT-PCR assay for detection of SARS-CoV
Example explanation: It's a correct title because the paragraph described the development of 3 -noncoding region of SARS-CoV genome and assay efficiently detecting SARS-CoV from clinical specimens.
Q: The spike (S) protein of coronavirus, mouse hepatitis virus (MHV), mediates attachment and fusion during viral entry and cell-to-cell fusion later in infection. By analogy with other viral proteins that induce cell fusion the MHV S protein would be expected to have a hydrophobic stretch of amino acids that serves as a fusion peptide. Sequence analysis suggests that the S protein falls within the group of fusion proteins having internal rather than N-terminal fusion peptides. Based on the features of known viral fusion peptides, we identified two regions (PEP1 and PEP2) of MHV-A59 S2 as possible fusion peptides. Site-directed mutagenesis and an in vitro cell-to-cell fusion assay were used to evaluate the roles of PEP1 and PEP2, as well as a third previously identified putative fusion domain (PEP3) in membrane fusion. Substitution of bulky hydrophobic residues with charged residues within PEP1 affects the fusion activity of the S protein without affecting processing and surface expression. Similar substitutions within PEP2 result in a fusion-negative phenotype; however, these mutant S proteins also exhibit defects in protein processing and surface expression which likely explain the loss of the ability to induce fusion. Thus PEP1 remains a candidate fusion peptide, while PEP2 may play a significant role in the overall structure or oligomerization of the S protein. PEP3 is an unlikely putative fusion peptide since it is not conserved among coronaviruses and nonconservative amino acid substitutions in PEP3 have minimal effects on cell-to-cell fusion.
A:
Roles in Cell-to-Cell Fusion of Two Conserved Hydrophobic Regions in the Murine Coronavirus Spike Protein