{'fraction_non_alphanumeric': 0.025056947608200455, 'fraction_numerical': 0.002277904328018223, 'mean_word_length': 5.59, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Characterization and Crystal Structure of a Nonheme Diiron Monooxygenase Involved in Platensimycin and Platencin Biosynthesis.

Nonheme diiron monooxygenases make up a rapidly growing family of oxygenases that are rarely identified in secondary metabolism. Herein, we report the in vivo, in vitro, and structural characterizations of a nonheme diiron monooxygenase, PtmU3, that installs a C-5 -hydroxyl group in the unified biosynthesis of platensimycin and platencin, two highly functional-ized diterpenoids that act as potent and selective inhibitors of bacterial and mammalian fatty acid synthases. This hydroxyla-tion sets the stage for the subsequent A-ring cleavage step key to the unique diterpene-derived scaffolds of platensimycin and platencin. PtmU3 adopts an unprecedented triosephosphate isomerase (TIM)-barrel structural fold for this class of en-zymes and possesses a noncanonical diiron active site architecture with a saturated six-coordinate iron center lacking a μ-oxo bridge. This study reveals the first member of a previously unidentified superfamily of TIM-barrel fold enzymes for met-al-dependent dioxygen activation, with the majority predicted to act on CoA-linked substrates, thus expanding our knowledge of nature's repertoire of nonheme diiron monooxygenases and TIM-barrel fold enzymes.