Figure 1.

Secondary structure of domain V of E. coli 23S rRNA with post-transcriptional modifications. Inset shows the chemical structure of 5-hydroxycytidine (ho⁵C). The other modifications (blue) in this region are 7-methylguanosine (m⁷G) at position 2069, N²-methylguanosine (m²G) at position 2445, dihydrouridine (D) at position 2449, pseudouridine (Ψ) at positions 2457, 2504, 2580, 2604 and 2605, 2’-O-methylcytidine (Cm) at position 2498, 2-methyladenosine (m²A) at position 2503, and 2’-O-methyluridine (Um) at position 2552. Helix and position numbers are indicated. Two arrowheads indicate the RNase T₁ cleavage sites for the ho⁵C2501-containing fragment.