Hydrogen Exchange Study of DNA Duplexes Containing the Consensus Binding Site for Arabidopsis thaliana SPL14 Transcription Factor

摘要

In plants, programmed cell death (PCD) is required for proper growth and tracheary element differentiation. PCD also plays the important role in the plant defense against pathogen attack. Mis-expression of Arabidopsis thaliana SPL14 (AtSPL14) gene affects resistance to PCD and modification of plant architecture. AtSPL14 is a DNA-binding transcription factor, including a Cys-and His-rich SQUAMOSA promoter binding protein (SBP) domain. SBP is defined as a conserved approximately 80 amino acid domain. SBPs have roles in plant growth, metal sensing in algae, and directing development of leaves, embryos, and floral organs. However, the molecular basis on the physiological functions of AtSPL14 in regulating plant PCD and/or development is not completely understood. NMR structures of SBP domains indicate that SBP forms a unique DNA-binding domain consisting of two Zn-finger structures. Recently, the DNA consensus sequence (GTAC) for AtSPL14 binding was identified by systematic evolution of ligands by exponential enrichment (SELEX) or random binding site selection. It was reported that the GTAC consensus sequence required one or two additional flanking nucleotides for effective AtSPL14-DNA interaction.