Development of a system for the study of protein-protein interactions in planta: characterization of a TATA-box binding protein complex in Oryza sativa.

We describe a simple, rapid method for protein complex purification in planta. Using a biotin peptide as an affinity tag with TATA-box binding protein (TBP), 86 unique proteins present in the purified complex were identified by tandem mass spectrometry. We identified proteins known to be associated with TBP, and many other proteins involved in pre-mRNA processing and chromatin remodeling. The identification of these novel protein-protein associations will upon further investigations provide new insights into the mechanisms of mRNA transcription and pre-mRNA processing.