The presented crystallization case combines several practical approaches that should always be considered in difficult situations. Many cell surface receptors are multidomain molecules that are conformationally flexible but can be stabilized through interactions with the natural ligands or antibodies. We employed the latter approach to crystallizing the extracellular portion of a cell surface receptor alpha chain. Multiple expression constructs of the 3-domain molecule were tried. Based on the expression levels, the variant comprising domains 2 and 3 was chosen. Crystallization of this molecule in complex with the Fab fragment of the receptor-specific antibody was successful but yielded crystals that contained only the Fab. To avoid formation of Fab crystals, the smaller Fv fragment (scFv) was used. The receptor-scFv complex was formed but failed to yield any crystal hits. Therefore the complex was subjected to subtilisin treatment. Crystallization using microseed matrix screening resulted in the crystals of the complex. The structure was determined and analyzed to explain how the cleavage of the VL-VH linker in scFv promoted crystallization of the scFv complex.