血红素的自由基 SAM 依赖性脱金属
ヘムのラジカルSAM依存性脱金属
헴의 라디칼 SAM-의존성 탈금속화
Desmetalización radical dependiente de SAM del hemo
Démétallation radicale SAM-dépendante de l'hème
Радикальное SAM-зависимое деметаллирование гема
Jinduo Cheng 程金铎 ¹, Wei Ding 丁伟 ², Qi Zhang 张琪 ¹
¹ Department of Chemistry, Fudan University, Shanghai, 200433 China
中国 上海 复旦大学化学系
² State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
中国 上海 上海交通大学生命科学技术学院 微生物代谢国家重点实验室
Demetallation of heme to release iron is a chemical difficult reaction and is highly rare in biochemistry, with apoferritin as the only known enzyme responsible for this process. Here we show the heme degradation enzyme ChuW catalyzes heme demetallation besides its known methyltransferase activity (which converts heme to a ring-open product anaerobilin).
We show the demetallation activity of ChuW is radical SAM-dependent, and likely involves the same set of intermediates involved in the anaerobilin-producing pathway. The ChuW-catalyzed demetallation reaction does not require external reductant, and can occur on several heme analogs with different metal centers. These findings establish a brand-new chemistry in the radical SAM enzymes, highlighting the remarkable catalytic diversity of this superfamily of enzymes.
