Figure 2. Crystal structure of the RasGRP1 autoinhibited catalytic module.
(A) A crystal structure of the first four domains of RasGRP1 shows the REM domain (blue) buttressing the helical hairpin of the Cdc25 domain (green). The EF domain (magenta) is sandwiched between one side of the Cdc25 domain and the C1 domain (teal). Two zinc ions in the C1 domain are shown as gray spheres. The Cdc25-EF linker (red) traverses the Ras-binding site on the Cdc25 domain. Linkers that could not be modeled due to poor electron density are shown with dotted lines. The N- and C-termini are indicated by N and C, respectively. (B) The C1 domain mediates formation of a crystallographic dimer. The domains of one monomer are denoted with primes.
Figure 2—figure supplement 1. The Cdc25-EF linker occupies the Ras binding site in the Cdc25 domain.
The electron density from a kick omit map without the Cdc25-EF linker is shown in orange mesh at 2.5σ (Fo-Fc).