Related to Figures
S1.
(A) Schematic representation of LIN28 protein domains.
(B, C) The ZKD and CSD binding motifs determined from
single-nucleotide-resolution analysis of CLIP data. A GGAG-like motif was
identified by modeling sequences around LIN28A CIMS derived from mouse ESCs (B,
right panel), and a UGAU motif was determined by modeling sequences around
LIN28B CITS derived from K562 cells (C, right panel). The frequency of
crosslinking at each motif position is shown under the motif logos. The
enrichment of GGAG and UGAU tetramers around CIMS or CITS is shown on the left
of each panel.
(D, E) The crystal structure of LIN28A ZKD (D) and CSD (E) in complex
with let-7g hairpin (PDB accession: 3TS2). Residues that are in direct contact
with RNA are highlighted in blue. The crosslinked nucleotides are indicated in
red and highlighted.
(F) Frequency of tetramers conforming to the NGAU consensus in LIN28B
eCLIP data from K562 cells. The fold enrichment of each tetramer at the
crosslink site in comparison to matched control sequences is shown in the
parentheses.
(G) CSD binding motifs identified from RBNS analysis. The most enriched
pentamers and hexamers after two rounds of LIN28A CSD selection are shown.
(H) Enrichment of NGAU and GGAG around LIN28 eCLIP tag cluster peaks
from K562 cells.