Figure 6.
Figure 6. Interaction of the Sso core primase with DNA template
and RNA primer. (a) The zinc-binding motif of archaeal
primases. The small subunits of Sso, Pho (PDB entry 1V33) and
Sis (PDB entry 1RNI) primases were superimposed. The Sso
PriS-prim is shown as a molecular surface. The zinc-binding
motifs of Sso (green), Pho (yellow) and Sis (pink) are narrow
tubes and their zinc atoms are spheres. (b) Comparison of the
enzymatic activity of wild-type Sso core primase (Pri-WT) with
that of the RR and SNG mutants (Pri-RR and Pri-SNG,
respectively). Experiments were performed as for Figure 1c. DN,
dinucleotide product. (c) Comparison of the quantities of
product synthesized by Pri-WT and the RR and SNG mutants.
Experiments were performed as for Figure 1c, with 1.2 M
primase concentration. The radiolabeled products were quantified
by filter binding and liquid scintillation counting. Each bar
represents the average of five independent values with s.e.m.
indicated. (d) Model of the Sso core primase-DNA template-RNA
primer complex. The protein component of the complex is depicted
as a molecular surface. The phosphate backbones of DNA and RNA
are orange and cyan tubes, respectively. The proposed trajectory
of the template DNA across the surface of the core primase is
drawn. The position of PriS-Zn and the putative position of
PriL-CTD are indicated by solid and dashed circles,
respectively. The side chains of basic residues on and near PriL
5
are blue. The positions of PriL residues Arg84 and Arg85 are
indicated.
The above figure is reprinted
by permission from Macmillan Publishers Ltd:
Nat Struct Mol Biol
(2005,
12,
1137-1144)
copyright 2005.
M
primase concentration. The radiolabeled products were quantified
by filter binding and liquid scintillation counting. Each bar
represents the average of five independent values with s.e.m.
indicated. (d) Model of the Sso core primase-DNA template-RNA
primer complex. The protein component of the complex is depicted
as a molecular surface. The phosphate backbones of DNA and RNA
are orange and cyan tubes, respectively. The proposed trajectory
of the template DNA across the surface of the core primase is
drawn. The position of PriS-Zn and the putative position of
PriL-CTD are indicated by solid and dashed circles,
respectively. The side chains of basic residues on and near PriL
5
are blue. The positions of PriL residues Arg84 and Arg85 are
indicated.