Crystallization of a 79 kDa fragment of the hook protein FlgE from Campylobacter jejuni

A 79 kDa fragment of the bacterial flagellar hook protein FlgE from Campylobacter jejuni was cloned, overexpressed, purified and crystallized. Two different crystal forms were obtained. Synchrotron X‐ray diffraction data showed that the first crystal form, which diffracted to 4.9 Å resolution, belonged to the tetragonal crystal system, with space group I4122 and unit‐cell parameters a = b = 186.2, c = 386.6 Å, α = β = γ = 90°. The second crystal form diffracted to 2.5 Å resolution and belonged to the monoclinic crystal system, with space group P21 and unit‐cell parameters a = 75.7, b = 173.8, c = 150.8 Å, α = γ = 90, β = 106.5°. SeMet protein was also overexpressed, purified and crystallized, and a 2.6 Å resolution MAD data set was collected.