|
Figure 2.
Figure 2. The nucleotide binding pocket of PspF[1-275]
modelled on the structure of Click to view the MathML source- [0?wchp=dGLbVzb-zSkWA]
. (a) Final 2F[o] -F[c] map of the Mg2+-ATP and surrounding
water molecules at 2.1 Å resolution. The green arrow
points to the Mg2+ and the dark green arrow points to the apical
water molecule thought to be responsible for nucleophilic
attack. (b) Details of the largely hydrophobic adenine ring
binding pocket. The structures of apo (white), ATP (pink) and
ADP (blue) are superposed and side-chains of residues involved
in packing the purine base are shown as sticks. (c) Details of
the interactions around the phosphate backbone. The R227
side-chain is modelled on the ATP-PspF[1-275] structure.
Side-chains of residues of the Walker A motif (K42-E43), Walker
B motif (D107-D108) and sensor II motif (R227, K230, N231) are
shown as sticks in their different nucleotide states (apo in
white, ATP in pink and ADP in blue). Also appearing as sticks
are residues N64 and S62, responsible for relaying the
conformational signal to L1. Hexa-coordination of the Mg2+ is
highlighted by magenta dotted lines. The interactions
surrounding the water molecule, thought to be responsible for
the nucleophilic attack, are highlighted by yellow dotted lines.
|
