Figure 3.
Figure 3: Specific recognition of a hemi-methylated CpG site by
SRA. The colour codes for the protein and DNA are same as in
Fig. 2a. Red dotted lines show hydrogen-bond contacts within 4
Å. a, Close-up view of the flipped-out 5mC[7] recognition
site. The composite-omit electron density map for 5mC[7] (more
than 6.0 )
is shown in blue. b, The orphaned guanidine G[7]' base is
retained near a canonical position in the DNA duplex by
interactions with the SRA residues. c, Interactions between the
G8 C8'
base pair adjacent to the flipped-out base and the SRA residues.
Wat, water. d, The model of fully methylated DNA bound to the
SRA. The methyl group of 5mC[8]' (shown as a green sphere)
causes steric interference with Asn 494 (orange spheres) in the
finger loop. The hydrogen-bond distances between these bases and
the SRA residues are listed in Supplementary Tables 2 and 3.
The above figure is reprinted
by permission from Macmillan Publishers Ltd:
Nature
(2008,
455,
818-821)
copyright 2008.
)
is shown in blue. b, The orphaned guanidine G[7]' base is
retained near a canonical position in the DNA duplex by
interactions with the SRA residues. c, Interactions between the
G8 
C8'
base pair adjacent to the flipped-out base and the SRA residues.
Wat, water. d, The model of fully methylated DNA bound to the
SRA. The methyl group of 5mC[8]' (shown as a green sphere)
causes steric interference with Asn 494 (orange spheres) in the
finger loop. The hydrogen-bond distances between these bases and
the SRA residues are listed in Supplementary Tables 2 and 3.