Figure 3.
Figure 3. Positioning of the Transcription Start Site at the
vRNAP Active Site A view of the P2_7a promoter-binary
complex active center. Thumb and plug are removed to see the
active center. Residue R318 in the N-terminal domain has a
cation-π interaction with base −2 and salt bridges with the
phosphate backbone (depicted by yellow and green dashed lines,
respectively) that induce a DNA kink between bases −2 and
−1. The +3 base is rotated by vert,
similar 90°, presenting only DNA bases from −1 to +2 to
the active site. Amino acid residues essential for activity at
the active site are shown: R424 (T/DxxGR motif) for substrate
binding; D559 (motif A) and D951 (motif C) for chelating the
catalytically essential Mg^2+ ions; and R666, K670, and Y678
(motif B) for substrate binding. The boxed area is magnified.
The above figure is reprinted
from an Open Access publication published by Cell Press:
Mol Cell
(2008,
32,
707-717)
copyright 2008.
vert,
similar 90°, presenting only DNA bases from −1 to +2 to
the active site. Amino acid residues essential for activity at
the active site are shown: R424 (T/DxxGR motif) for substrate
binding; D559 (motif A) and D951 (motif C) for chelating the
catalytically essential Mg^2+ ions; and R666, K670, and Y678
(motif B) for substrate binding. The boxed area is magnified.