7MC4

Crystal structure of a single-chain E/F type bilin lyase-isomerase MpeQ

7MC4 の概要

• エントリーDOI: 10.2210/pdb7mc4/pdb
• 分子名称: Bilin Lyase-Isomerase (2 entities in total)
• 機能のキーワード: bilin lyase-isomerase, lyase
• 由来する生物種: Synechococcus sp. P1
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 93357.93

構造登録者

Yang, X.,Kumarapperuma, I. (登録日: 2021-04-01, 公開日: 2022-02-23, 最終更新日: 2024-10-23)

主引用文献

Kumarapperuma, I.,Joseph, K.L.,Wang, C.,Biju, L.M.,Tom, I.P.,Weaver, K.D.,Grebert, T.,Partensky, F.,Schluchter, W.M.,Yang, X.
Crystal structure and molecular mechanism of an E/F type bilin lyase-isomerase.
Structure, 30:564-, 2022

PubMed Abstract: Chromophore attachment of the light-harvesting apparatus represents one of the most important post-translational modifications in photosynthetic cyanobacteria. Extensive pigment diversity of cyanobacteria critically depends on bilin lyases that covalently attach chemically distinct chromophores to phycobiliproteins. However, how bilin lyases catalyze bilin ligation reactions and how some lyases acquire additional isomerase abilities remain elusive at the molecular level. Here, we report the crystal structure of a representative bilin lyase-isomerase MpeQ. This structure has revealed a "question-mark" protein architecture that unambiguously establishes the active site conserved among the E/F-type bilin lyases. Based on structural, mutational, and modeling data, we demonstrate that stereoselectivity of the active site plays a critical role in conferring the isomerase activity of MpeQ. We further advance a tyrosine-mediated reaction scheme unifying different types of bilin lyases. These results suggest that lyases and isomerase actions of bilin lyases arise from two coupled molecular events of distinct origin.

PubMed: 35148828
DOI: 10.1016/j.str.2022.01.007

実験手法

X-RAY DIFFRACTION (2.5 Å)