3SL7

Crystal structure of CBS-pair protein, CBSX2 from Arabidopsis thaliana

Summary for 3SL7

• Entry DOI: 10.2210/pdb3sl7/pdb
• Descriptor: CBS domain-containing protein CBSX2, ACETATE ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: cbs-pair protein, redox regulator, plant cbs domain, thioredoxin, chloroplast, membrane protein
• Biological source: Arabidopsis thaliana (thale-cress)
• Cellular location: Plastid, chloroplast stroma: Q9C5D0
• Total number of polymer chains: 2
• Total formula weight: 40197.53

Authors

Jeong, B.-C.,Lee, M.-R.,Song, H.K. (deposition date: 2011-06-24, release date: 2011-11-09, Last modification date: 2024-10-16)

Primary citation

Yoo, K.S.,Ok, S.H.,Jeong, B.-C.,Jung, K.W.,Cui, M.H.,Hyoung, S.,Lee, M.-R.,Song, H.K.,Shin, J.S.
Single cystathionine beta-synthase domain-containing proteins modulate development by regulating the thioredoxin system in Arabidopsis
Plant Cell, 23:3577-3594, 2011

PubMed Abstract: Plant thioredoxins (Trxs) participate in two redox systems found in different cellular compartments: the NADP-Trx system (NTS) in the cytosol and mitochondria and the ferredoxin-Trx system (FTS) in the chloroplast, where they function as redox regulators by regulating the activity of various target enzymes. The identities of the master regulators that maintain cellular homeostasis and modulate timed development through redox regulating systems have remained completely unknown. Here, we show that proteins consisting of a single cystathionine β-synthase (CBS) domain pair stabilize cellular redox homeostasis and modulate plant development via regulation of Trx systems by sensing changes in adenosine-containing ligands. We identified two CBS domain-containing proteins in Arabidopsis thaliana, CBSX1 and CBSX2, which are localized to the chloroplast, where they activate all four Trxs in the FTS. CBSX3 was found to regulate mitochondrial Trx members in the NTS. CBSX1 directly regulates Trxs and thereby controls H(2)O(2) levels and regulates lignin polymerization in the anther endothecium. It also affects plant growth by regulating photosynthesis-related [corrected] enzymes, such as malate dehydrogenase, via homeostatic regulation of Trxs. Based on our findings, we suggest that the CBSX proteins (or a CBS pair) are ubiquitous redox regulators that regulate Trxs in the FTS and NTS to modulate development and maintain homeostasis under conditions that are threatening to the cell.

PubMed: 22021414
DOI: 10.1105/tpc.111.089847

Experimental method

X-RAY DIFFRACTION (1.905 Å)