2-D Structure of the A Region of Xist RNA and Its Implication for PRC2 Association
The two RNAs (A. for 5′ terminal 1137-nt long RNA, B. for A region) were in vitro transcribed and renatured as described in Material and Methods, before being subjected to limited digestion with T1, T2, or V1 RNases under the conditions described in Materials and Methods. Extension analyses were performed using oligonucleotide 3866 (Table S1) as the primer. The resulting cDNAs were fractionated by electrophoresis on 7% denaturing polyacrylamide gel. Lanes U, G, C, and A correspond to the sequencing ladder obtained with the same primer. Lanes marked by Contr corresponds to primer extension analysis of undigested RNA transcripts. Nucleotide numbering on the left-hand side of the autoradiogram takes the first residue of mouse Xist RNA as residue 1. The sequences corresponding to repeats 3 and 4 are indicated by vertical bars on the right-hand side of the autoradiograms.