Cinnamoyl-containing natural products (CCNPs) are a small class of bacterial metabolites with notable bioactivities. The biosynthesis of cinnamoyl moiety has been proposed to be assembled by an unusual highly reducing (HR) type II polyketide synthases (PKS). However, the biosynthetic route, especially the cyclization step for the benzene ring formation, remains unclear. In this work, we successfully reconstituted the pathway of cinnamoyl moiety in kitacinnamycin biosynthesis through a step-wise approach in vitro and demonstrated that a three-protein complex, Kcn17–Kcn18–Kcn19, can catalyze 6π-electrocyclization followed by dehydrogenation to form the benzene ring. We found that the three-protein homologues were widely distributed among 207 HR type II PKS biosynthetic gene clusters including five known CCNPs. In contrast, in the biosynthesis of youssoufene, a cinnamoyl-containing polyene, we identified that the benzene ring formation was accomplished by a distinct orphan protein. Thus, our work resolved the long-standing mystery in cinnamoyl biosynthesis and revealed two distinct enzymes that can synthesize benzene rings via polyene precursors.

According to our limited data, most patients with CN palsy respond well to RT. That the time course of neurologic recovery is variable and can be protracted indicates a need for continuous and close neurologic surveillance. The poorer neurologic outcome associated with a longer duration of CN symptoms may be related to a more severe longterm CN compression that results in irreversible damage. Timely diagnosis of NPC and fast institution of therapy are therefore critical to improving the neurologic outcome.

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The radio frequency identification technology is a kind of emerging non-contact identification technology. In the study of radio frequency identification reader, the traditional microcontroller-based architecture can’t meet the system requirements due to the limited processing ability. In this paper, the author designs a UHF RFID reader based on the ARM processor and FPGA, compared to the microcontroller-based architecture, the reader deals faster. The reader consists of three parts, namely, the protocol processing module, the digital baseband module and the RF module.