The S2 subunit of the murine coronavirus spike protein is not involved in receptor binding.
The receptor-binding capacity of the S2 subunit of the murine coronavirus S protein was examined by testing the inhibition of virus-receptor binding. Sp-4 virus and S1N(330), which consists of the N-terminal 330 amino acids of the S1 protein, both of which exhibited receptor-binding capacity, were able to prevent the binding of cl-2 virus to the receptor, while the mutant protein S1N(330)-159, which failed to bind to the receptor protein, and S2TM-, which lacks the transmembrane and cytoplasmic domains normally existing in the S2, were unable to prevent the binding of cl-2. By using cultured DBT cells, it was revealed that the infection of cells by cl-2 virus was significantly inhibited by S1N(330) but not by S2TM-. These results indicate that the S2 protein is not involved in the receptor binding of murine coronaviruses.
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D015153:Blotting, Western; D002462:Cell Membrane / Q000502:physiology; D017934:Coronavirus / Q000502:physiology*; D017931:DNA Primers; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D000085064:Receptors, Coronavirus; D011991:Receptors, Virus / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D017384:Sequence Deletion; D064370:Spike Glycoprotein, Coronavirus; D014162:Transfection; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*
D017931:DNA Primers; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D000085064:Receptors, Coronavirus; D011991:Receptors, Virus; D011994:Recombinant Proteins; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus