ID   2.3.1.290
DE   spectinabilin polyketide synthase system.
AN   spectinabilin polyketide synthase complex.
CA   4-nitrobenzoyl-CoA + 6 (S)-methylmalonyl-CoA + malonyl-CoA + 6 NADPH +
CA   12 H(+) = demethyldeoxyspectinabilin + 7 CO2 + 6 NADP(+) + 8 CoA + 5 H2O.
CC   -!- This polyketide synthase, characterized from the bacteria
CC       Streptomyces orinoci and Streptomyces spectabilis, generates the
CC       backbone of the antibiotic spectinabilin.
CC   -!- It is composed of 6 modules that total 28 domains and is encoded by
CC       four genes.
CC   -!- The enzyme accepts the unusual starter unit 4-nitrobenzoyl-CoA and
CC       extends it by 6 molecules of (S)-methylmalonyl-CoA and a single
CC       molecule of malonyl-CoA.
CC   -!- The first module (encoded by norA) is used twice in an iterative
CC       fashion, so that the seven Claisen condensation reactions are
CC       catalyzed by only six modules.
CC   -!- The iteration becomes possible by the transfer of the [acp]-bound
CC       polyketide intermediate back to the ketosynthase (KS) domain on the
CC       opposite polyketide synthase strand (polyketides are homodimeric).
DR   B4ER95, NORA2_STRON;  B4ER92, NORA_STRON ;  B4ER96, NORB_STRON ;
DR   B4ER97, NORC_STRON ;
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