Cloning, expression, crystallization and preliminary X-ray analysis of the first two Ig domains from human Roundabout 1 (Robo1)

Activation of Roundabout 1 (Robo1) by Slit proteins results in axon repulsion from the midline. Robo1 is a large transmembrane receptor expressed on the axon growth cone and the minimal Robo1‐binding region required for Slit activation has been mapped to the N‐terminal Ig1–2 domains. The cDNA encoding the first two Ig domains of Robo1 has been cloned and the protein has been expressed in HEK293 EBNA‐1 mammalian cells. Here, the purification and crystallization conditions of this Robo1 construct are reported. The crystals are orthorhombic, space group P21212, with unit‐cell parameters a = 38.8, b = 69.4, c = 103.3 Å and one molecule in the asymmetric unit. X‐ray diffraction data have been collected to 2.8 Å resolution on beamline ID29 at the ESRF.