Cloning, expression, and purification of small subunit human ribosomal proteins SA/uS2, S2/uS5, S3/uS3, S7/eS7, S8/eS8, S12/eS12, S13/uS15, and S14/uS11 for in vitro characterization.

A recent paper describes an improved method for producing human ribosomal proteins in the soluble fraction of bacterial lysates rather than in inclusion bodies. We have extended this approach to clone, express, and purify additional proteins from the small ribosomal subunit for use in enzymatic and structural assays, as well as protein-protein interaction studies. Here, we show that an N-terminal 6×His-Trx tag enables the soluble expression and purification of human RPS3/uS3, RPS12/eS12, and RPS14/uS11 from E. coli cells. These results expand the repertoire of human ribosomal proteins available for individual characterization outside of the intact ribosomal complex.