Fig. 1

NLP-NLP interactions mediated by the PB1 domain in yeast. a Alignment of amino acid sequences of PB1 domains from Arabidopsis NLP transcription factors, human PKC1/λ, and an unrelated Arabidopsis protein (At3g52590). Black and gray backgrounds indicate identical and similar residues, respectively. Blue boxes mark core residues in Type I and Type II motifs. b Y2H assays with the PB1 domain of NLP7 (residues 853–949) as prey and wild-type NLP7 (amino acid residues 116–959), NLP7 containing mutations in the PB1 domain (K867, D909, D111, and E913 replaced with alanine residues), or NLP7 lacking the PB1 domain (residues 116–863) as bait. GBD and AD are the DNA-binding and transactivation domains of yeast Gal4, respectively; AD also contains a nuclear localization signal. c Y2H β-galactosidase assays to determine interactions between NLP PB1 domains. Numbers in parentheses indicate the amino acid residues used in the GBD and AD fusion constructs. For each GBD fusion construct, the upper and lower images show cell growth and β-galactosidase activity, respectively