Stable mammalian producer cell lines for structural biology.

The mammalian cell lines HEK293 and CHO have become important expression hosts in structural biology. Generating stable mammalian cell lines remains essential for studying the function and structure of recombinant proteins, despite the emergence of highly efficient transient transfection protocols. Production with stable cell lines can be scaled up easily and high volumetric product yield can be achieved. Protein structure reports of the past two years that used stable cell lines were surveyed for this review. Well-established techniques and novel approaches for generating stable cell lines and stable cell pools are presented, including cell sorting, site-specific recombination, transposons, the Lentivirus system and phage integrases. Host cell line optimization by endoglycosidase overexpression and sequence-specific genome engineering is highlighted.