Figure 3.
Fig. 3. (A) Map showing the initial electron density for
the inserted region of molecule A in space group P2[1].
Amplitudes are (2F[o]-F[c]) weighted by REFMAC (15) where the
structure factors, F[c], and phases were calculated from the
refined model including the inserted region. The map was
calculated at 2.5-Å resolution and contoured at 1.0 . The
density in the vicinity of residues 40i-43i is not well defined
and could not be fit by a well-defined model. (B) Electron
density for molecule B of crystal form P2[1]. This map was
calculated with the same coefficients, contouring, and
resolution as in A. (C) Superposition of the C trace of
the two copies of mutant L20 in crystal form P2[1] (molecule A,
blue; molecule B, mauve) and wild-type T4 lysozyme (green). The
sequence of the insert is highlighted in yellow for molecule A
and in orange for molecule B. The structural rearrangements of
loop 18-25 in molecule B are clearly visible. The superpositions
were based on the -carbon
atoms of residues 51-80 within the amino-terminal domain.
Because of slight changes in the hinge-bending angle the
C-terminal domains appear out of register although the
respective structures within these regions are very similar.
. The
density in the vicinity of residues 40i-43i is not well defined
and could not be fit by a well-defined model. (B) Electron
density for molecule B of crystal form P2[1]. This map was
calculated with the same coefficients, contouring, and
resolution as in A. (C) Superposition of the C 
trace of
the two copies of mutant L20 in crystal form P2[1] (molecule A,
blue; molecule B, mauve) and wild-type T4 lysozyme (green). The
sequence of the insert is highlighted in yellow for molecule A
and in orange for molecule B. The structural rearrangements of
loop 18-25 in molecule B are clearly visible. The superpositions
were based on the