9M74

Crystal structure of MBP-fused BIL1/BZR1 (21-104) in complex with double-stranded DNA contaning CACAGCTGTG

Summary for 9M74

• Entry DOI: 10.2210/pdb9m74/pdb
• Related PRD ID: PRD_900001
• Descriptor: Maltodextrin-binding protein,Protein BRASSINAZOLE-RESISTANT 1, DNA (5'-D(*TP*TP*CP*AP*CP*AP*GP*CP*TP*GP*TP*GP*AP*AP*A)-3'), alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, ... (5 entities in total)
• Functional Keywords: plant-specific, dna-biding protein, transcription factor, bzr, dna binding protein
• Biological source: Arabidopsis thaliana (thale cress); More
• Total number of polymer chains: 8
• Total formula weight: 219205.22

Authors

Shohei, N.,Masaru, T.,Takuya, M. (deposition date: 2025-03-09, release date: 2025-09-10, Last modification date: 2025-12-10)

Primary citation

Nosaki, S.,Ohtsuka, M.,Nakano, T.,Tanokura, M.,Miyakawa, T.
Single cis-elements in brassinosteroid-induced upregulated genes are insufficient to recruit both redox states of the BIL1/BZR1 DNA-binding domain.
Febs Lett., 599:3369-3380, 2025

PubMed Abstract: The plant-specific transcription factor BRZ-INSENSITIVE-LONG 1 (BIL1)/BRASSINAZOLE-RESISTANT 1 (BZR1) regulates the growth of Arabidopsis thaliana via brassinosteroid signaling, acting as both a gene repressor and activator. Its upregulation requires environmental cues mediated by PHYTOCHROME INTERACTING FACTOR 4 (PIF4), with oxidative modifications via HO enhancing their interaction. However, the nature of the tripartite complex of cis-elements, BIL1/BZR1, and PIF4 under redox changes remains unclear. Here, we demonstrate that oxidation of the DNA-binding domain (DBD) of BIL1/BZR1 alters its DNA-binding ability. However, single cis-elements enriched in brassinosteroid-induced genes do not support binding of either redox form, nor does BIL1/BZR1 DBD heterodimerize with PIF4 DBD on these elements. These findings highlight the complexity of brassinosteroid transcriptional regulation beyond DNA-binding specificity and redox modifications.

PubMed: 40882013
DOI: 10.1002/1873-3468.70147

Experimental method

X-RAY DIFFRACTION (2.23 Å)