title: Effects of the Methylmalonyl-CoA Metabolic Pathway on Ansamitocin Production in Actinosynnema pretiosum.
abstract: Ansamitocins, which may have antitumor activity, are important secondary metabolites produced by Actinosynnema pretiosum sp. auranticum ATCC 31565. As one of the precursors for ansamitocin biosynthesis, methylmalonyl-CoA may be a critical metabolic node for secondary metabolism in A. pretiosum. In this study, we investigated two key enzymes related to the methylmalonyl-CoA metabolic pathway: methylmalonyl-CoA mutase (MCM) and propionyl-CoA carboxylase (PCC). For MCM, inactivation of the asm2277 gene (encoding the large subunit of MCM) resulted in 3-fold increase in ansamitocin P-3 (AP-3) production (reaching 70 mg/L) compared with that in wild-type A. pretiosum. The three genes responsible for PCC were asm6390, encoding propionyl-CoA carboxylase beta chain, and asm6229 and asm6396, which encoded biotin carboxylases, respectively. Heterogeneous overexpression of the amir6390 gene alone and concurrent overexpression of amir6390 with both amir6396 and amir6229 were carried out, and the resulting engineered strains could produce AP-3 at levels that were 1.6-fold and 3-fold (28.3 and 51.5 mg/L in flask culture, respectively) higher than that in the wild-type strain. These results suggested that eliminating the bypass pathways and favoring the precursor synthetic pathway could effectively increase ansamitocin production in A. pretiosum.
authors: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
authors: Mengjiang
authors: M
authors: Zhao
authors: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
authors: Yuxiang
authors: Y
authors: Fan
authors: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
authors: Liujing
authors: L
authors: Wei
authors: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China. hufx@ecust.edu.cn.
authors: Fengxian
authors: F
authors: Hu
authors: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China. qhua@ecust.edu.cn.|Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai, 200237, China. qhua@ecust.edu.cn.
authors: Qiang
authors: Q
authors: Hua
mesh_terms: D039903:Actinobacteria / Q000235:genetics / Q000378:metabolism; D000214:Acyl Coenzyme A / Q000235:genetics / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000378:metabolism*; D008453:Maytansine / Q000031:analogs & derivatives* / Q000096:biosynthesis
chemical_list: D000214:Acyl Coenzyme A; D000970:Antineoplastic Agents; C015357:methylmalonyl-coenzyme A; D008453:Maytansine; C015682:ansamitocins
keywords: Actinosynnema pretiosum; Ansamitocins; Methylmalonyl-CoA mutase; Propionyl-CoA carboxylase