文献类型：期刊文献

英文题名：The cyanobacterial ornithine-ammonia cycle involves an arginine dihydrolase

作者：Zhang, Hao[1,2];Liu, Yujie[1,2];Nie, Xiaoqun[1,2];Liu, Lixia[1];Hua, Qiang[3];Zhao, Guo-Ping[1,4,5,6,7];Yang, Chen[1]

机构：[1]Chinese Acad Sci, Shanghai Inst Plant Physiol & Ecol, CAS Ctr Excellence Mol Plant Sci, CAS Key Lab Synthet Biol, Shanghai, Peoples R China;[2]Univ Chinese Acad Sci, Beijing, Peoples R China;[3]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai, Peoples R China;[4]Fudan Univ, Sch Life Sci, Dept Microbiol & Microbial Engn, State Key Lab Genet Engn, Shanghai, Peoples R China;[5]Fudan Univ, Sch Life Sci, Dept Microbiol & Microbial Engn, Ctr Synthet Biol, Shanghai, Peoples R China;[6]Chinese Univ Hong Kong, Prince Wales Hosp, Dept Microbiol, Shatin, Hong Kong, Peoples R China;[7]Chinese Univ Hong Kong, Prince Wales Hosp, Li Ka Shing Inst Hlth Sci, Shatin, Hong Kong, Peoples R China

年份：2018

卷号：14

期号：6

起止页码：575

外文期刊名：NATURE CHEMICAL BIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000435445100014)】；

基金：The authors thank Y. Shan for technical assistance on hybrid quadrupole-orbitrap MS and J. Zhao for helpful discussions. This work was funded for C.Y. by the National Natural Science Foundation of China (31630003 and 31470168), the National Key R&D Program of China (2016YFC1303303), and the Chinese Academy of Sciences (XDPB0400).

语种：英文

摘要：Living organisms have evolved mechanisms for adjusting their metabolism to adapt to environmental nutrient availability. Terrestrial animals utilize the ornithine-urea cycle to dispose of excess nitrogen derived from dietary protein. Here, we identified an active ornithine-ammonia cycle (OAC) in cyanobacteria through an approach combining dynamic N-15 and C-13 tracers, metabolomics, and mathematical modeling. The pathway starts with carbamoyl phosphate synthesis by the bacterial-and plant-type glutamine-dependent enzyme and ends with conversion of arginine to ornithine and ammonia by a novel arginine dihydrolase. An arginine dihydrolase-deficient mutant showed disruption of OAC and severely impaired cell growth when nitrogen availability oscillated. We demonstrated that the OAC allows for rapid remobilization of nitrogen reserves under starvation and a high rate of nitrogen assimilation and storage after the nutrient becomes available. Thus, the OAC serves as a conduit in the nitrogen storage-and-remobilization machinery in cyanobacteria and enables cellular adaptation to nitrogen fluctuations.