BOB1: Proteins and Enzymes

BOB1 is a novel 35kDa protein designated Bob1 (B cell Oct binding protein 1) is a lymphocyte specific transcription co activator protein. B cell specific transcription is mediated by octamer motifs found in immunoglobulin heavy and light chain gene promoters and in some immunoglobulin enhancers. These sites are bound by the B cell specific Oct1 and Oct2 transcription factors, and the B cell restricted co activator BOB.1/OBF.1. This protein interacts only with the Oct1/2 proteins through sub domains in the POU domain of the Oct1/2 proteins, enhancing their transcriptional efficacy. Although having no intrinsic capacity for DNA binding, Bob1 associates tightly with the octomer motif in the presence of Oct1 and Oct2. Bob1 is expressed at highest levels in spleen and peripheral blood leukocytes.