New members of the tomato ERF family show specific expression pattern and diverse DNA-binding capacity to the GCC box element

Abstract

Four new members of the ERF (ethylene-response factor) family of plant-specific DNA-binding (GCC box) factors were isolated from tomato fruit (LeERF1-4). Phylogenetic analysis indicated that LeERF2 belongs to a new ERF class, characterized by a conserved N-terminal signature sequence. Expression patterns and cis/trans binding affinities differed between the LeERFs. Combining experimental data and modeled three-dimensional analysis, it was shown that binding affinity of the LeERFs was affected by both the variation of nucleotides surrounding the DNA cis-element sequence and the nature of critical amino acid residues within the ERF domain.