Molecular Biology Commons^™

The coat proteins of the RNA bacteriophages Qβ and MS2 are specific RNA binding proteins. Although they possess common tertiary structures, they bind different RNA stem loops and thus provide useful models of specific protein-RNA recognition. Although the RNA-binding site of MS2 coat protein has been extensively characterized previously, little is known about Qβ. Here we describe the isolation of mutants that define the RNA-binding site of Qβ coat protein, showing that, as with MS2, it resides on the surface of a large β-sheet. Mutations are also described that convert Qβ coat protein to the RNA binding specificity of MS2. …

The NF-kappaB/c-Rel proteins are a family of evolutionarily conserved transcription factors activated during development that in the adult, mediate many processes including the immune response. A high degree of sequence similarity is shared between the NF-kappaB/c-Rel family of transcription factors and the Drosophila Dorsal protein as well as between its cytoplasmic inhibitor, IkappaBalpha, and the Drosophila Cactus protein. Genetic analyses of Dorsal have defined components of a signaling pathway for Dorsal activation, including a serine/threonine kinase, Pelle, placed upstream of Dorsal and Cactus. We demonstrate that this pathway is likely to be conserved in mammals by the isolation of a …