Abstract
The NheA component of the
B. cereus
Nhe toxin was overexpressed in
E. coli
, purified and crystallized. Diffraction data were collected and processed to 2.05 Å resolution.
The nonhaemolytic enterotoxin (Nhe) of
Bacillus cereus
plays a key role in cases of
B. cereus
food poisoning. The toxin is comprised of three different proteins: NheA, NheB and NheC. Here, the expression in
Escherichia coli
, purification and crystallization of the NheA protein are reported. The protein was crystallized by the sitting-drop vapour-diffusion method using PEG 3350 as a precipitant. The crystals of NheA diffracted to 2.05 Å resolution and belonged to space group
C
2, with unit-cell parameters
a
= 308.7,
b
= 58.2,
c
= 172.9 Å, β = 110.6°. Calculation of
V
M
values suggests that there are approximately eight protein molecules per asymmetric unit.