An in-cluster Sfp-type phosphopantetheinyl transferase instead of the holo-ACP synthase activates the granaticin biosynthesis under natural physiological conditions. - Ming-Rong Deng; Sin Yu Chik; Yan Li; Honghui Zhu; Guohui Pan; Hui Jiang; Xudong Qu (Frontiers in Chemistry, 2024)