Abstract
The DNA repair enzyme Endonuclease IV from the thermophilic bacterium
Thermotoga Maritima MSB8 (reference sequence: NC_000853) has been expressed
in Escherichia coli and crystallized for X‐ray analysis. Thermotoga maritima
Endonuclease IV is a 287 amino‐acid protein with 32% sequence identity to the
Escherichia coli Endonuclease IV. The protein was purified to homogeneity and was
crystallized using the sitting drop vapor‐diffusion method. The protein crystallized
in the space group P61, with a composition of one biological molecule in the
asymmetric unit corresponding to a Mathew’s coefficient of 2.39 and a 47% solvent
fraction. The unit‐cell parameters for the crystals are a = 123.23 Å, b = 123.23 Å , c =
35.34 Å, α = β= 90°, γ= 120°. Microseeding and further optimization yielded crystals
with an X‐ray diffraction limit of 2.4 Å. A single 70˚ data set was collected and
processed resulting in an overall Rmerge and completeness of 9.5% and 99.3%
respectively.
