5T0F

Crystal structure of the Myc3 N-terminal domain [44-242] in complex with JAZ10 CMID domain [16-58] from arabidopsis

5T0F の概要

• エントリーDOI: 10.2210/pdb5t0f/pdb
• 関連するPDBエントリー: 4RQW 4RRU 4RS9
• 分子名称: Transcription factor MYC3, Protein TIFY 9 (3 entities in total)
• 機能のキーワード: transcriptional repression, jasmonate signaling, myc3, jaz10 cmid, alternative splicing, desensitization, transcription
• 由来する生物種: Arabidopsis thaliana (Mouse-ear cress); 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 26840.65

構造登録者

Ke, J.,Zhang, F.,Brunzelle, J.S.,He, S.Y.,Xu, H.E.,Melcher, K. (登録日: 2016-08-16, 公開日: 2017-01-25, 最終更新日: 2023-10-04)

主引用文献

Zhang, F.,Ke, J.,Zhang, L.,Chen, R.,Sugimoto, K.,Howe, G.A.,Xu, H.E.,Zhou, M.,He, S.Y.,Melcher, K.
Structural insights into alternative splicing-mediated desensitization of jasmonate signaling.
Proc. Natl. Acad. Sci. U.S.A., 114:1720-1725, 2017

PubMed Abstract: Jasmonate ZIM-domain (JAZ) transcriptional repressors play a key role in regulating jasmonate (JA) signaling in plants. Below a threshold concentration of jasmonoyl isoleucine (JA-Ile), the active form of JA, the C-terminal Jas motif of JAZ proteins binds MYC transcription factors to repress JA signaling. With increasing JA-Ile concentration, the Jas motif binds to JA-Ile and the COI1 subunit of the SCF E3 ligase, which mediates ubiquitination and proteasomal degradation of JAZ repressors, resulting in derepression of MYC transcription factors. JA signaling subsequently becomes desensitized, in part by feedback induction of JAZ splice variants that lack the C-terminal Jas motif but include an N-terminal cryptic MYC-interaction domain (CMID). The CMID sequence is dissimilar to the Jas motif and is incapable of recruiting SCF, allowing CMID-containing JAZ splice variants to accumulate in the presence of JA and to re-repress MYC transcription factors as an integral part of reestablishing signal homeostasis. The mechanism by which the CMID represses MYC transcription factors remains elusive. Here we describe the crystal structure of the MYC3-CMID complex. In contrast to the Jas motif, which forms a single continuous helix when bound to MYC3, the CMID adopts a loop-helix-loop-helix architecture with modular interactions with both the Jas-binding groove and the backside of the Jas-interaction domain of MYC3. This clamp-like interaction allows the CMID to bind MYC3 tightly and block access of MED25 (a subunit of the Mediator coactivator complex) to the MYC3 transcriptional activation domain, shedding light on the enigmatic mechanism by which JAZ splice variants desensitize JA signaling.

PubMed: 28137867
DOI: 10.1073/pnas.1616938114

実験手法

X-RAY DIFFRACTION (2.4 Å)