TSSK6, also known as testis-specific serine/threonine-protein kinase 6, is a member of the CAMK Ser/Thr protein kinase family. This protein contains one protein kinase domain. It is highly expressed in the testis and lowly expressed in the colon, prostate, thymus, small intestine, and peripheral blood leukocytes. It interacts with the heatshock proteins HSPA8, HSPCB, and HAPA1A; these interactions appear to be required for TSSK6 kinase activity. It plays a role in DNA condensation during postmeiotic chromatin remodeling. Otherwise, TSSK6 is required for sperm production and function. Recombinant human TSSK6 protein, fused to His-tag at N-terminus, was expressed in E.coli.