NMR characterization and ligand binding site of the stem–loop 2 motif from the Delta variant of SARS-CoV-2

Assignment of C2′–C5′ resonances via ¹³C-filtered NOESY and TOCSY spectra of selectively labeled s2m Delta samples. The resonance assignments for nucleotide C732 are annotated as an example. The notation of nucleotides corresponds to the position in the genome −29,000. (A) ¹³C-filtered NOESY of the aromatic to ribose region. (B) Overview of applied experiments for both selectively labeled samples and assignments derived from this. (C) fw-HCCH-TOCSY plane of nucleotide C732 (red) in overlay with a constant time HSQC (black) of the ribose region. The plane was selected via the H1′ chemical shift of nucleotide C732 (F1 = 5.3 ppm).