4. Consider the now dominant variant of the SARS-CoV-2 called the D614G mutation: (A) (C) Spike Nucleocapsid Membrane S1 subunit S2 subunit Envelope 6141 RNA viral genome NTD RBD FP HR1 HR2 TM CT (B)...

Genetics Question about COVID-19

Extracted text: 4. Consider the now dominant variant of the SARS-CoV-2 called the D614G mutation: (A) (C) Spike Nucleocapsid Membrane S1 subunit S2 subunit Envelope 6141 RNA viral genome NTD RBD FP HR1 HR2 TM CT (B) Binding site to ACE2 receptor in human cells N terminal domain S1 Fusion HR2 protein S2 HR1 Transmembrane domain and cytoplasmic tail Trends in Genetics a) The mutation changes an Aspartate (D, Asp) to a Glycine (G, Gly) at nucleotide position 614 (that's why it's called the D614G mutant) in the S1 subunit of the Spike protein. Using only the information above and a codon table, what are the mRNA codon sequences of the 2019-dominant and 2020-dominant Spike proteins? Note the figure above is not needed to answer the question. Report in 5' to 3' orientation b) What type of substitution is this? In your answer, address the following: The expected substitution in base sequence (e.g., A → C) If the mutation is synonymous, nonsynonymous, or a frameshift If the mutation is a transition or a transversion c) The mutation increases infectivity by reducing the stability of the Spike protein such that it can remain in the open conformation more often. The open conformation increases the chances of binding to the host ACE2 receptor, needed for entering host cells. Does this information surprise you at this point in the semester? Does it make sense that this mutant would quickly become the dominant variant across the globe? (Hint: Not trick questions; easy questions.)