title: Genetic dissection of the polyoxin building block-carbamoylpolyoxamic acid biosynthesis revealing the "pathway redundancy" in metabolic networks.
abstract: BACKGROUND
  Polyoxin, a peptidyl nucleoside antibiotic, consists of three building blocks including a nucleoside skeleton, polyoximic acid (POIA), and carbamoylpolyoxamic acid (CPOAA), however, little is known about the "pathway redundancy" of the metabolic networks directing the CPOAA biosynthesis in the cell factories of the polyoxin producer.
  
  
  RESULTS
  Here we report the genetic characterization of CPOAA biosynthesis with revealing a "pathway redundancy" in metabolic networks. Independent mutation of the four genes (polL-N and polP) directly resulted in the accumulation of polyoxin I, suggesting their positive roles for CPOAA biosynthesis. Moreover, the individual mutant of polN and polP also partially retains polyoxin production, suggesting the existence of the alternative homologs substituting their functional roles.
  
  
  CONCLUSIONS
  It is unveiled that argA and argB in L-arginine biosynthetic pathway contributed to the "pathway redundancy", more interestingly, argB in S. cacaoi is indispensible for both polyoxin production and L-arginine biosynthesis. These data should provide an example for the research on the "pathway redundancy" in metabolic networks, and lay a solid foundation for targeted enhancement of polyoxin production with synthetic biology strategies.
authors: Wenqing
authors: W
authors: Chen
authors: Daofeng
authors: D
authors: Dai
authors: Changchun
authors: C
authors: Wang
authors: Tingting
authors: T
authors: Huang
authors: Lipeng
authors: L
authors: Zhai
authors: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and School of Pharmaceutical Sciences, Wuhan University, 185 East Lake Road, Wuhan 430071, P,R, China. zxdeng@whu.edu.cn.
authors: Zixin
authors: Z
authors: Deng
mesh_terms: D000595:Amino Acid Sequence; D003198:Computer Simulation; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D008969:Molecular Sequence Data; D010072:Oxamic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D011741:Pyrimidine Nucleosides / Q000235:genetics
chemical_list: D011741:Pyrimidine Nucleosides; C002457:polyoxin; C015053:carbamoylpolyoxamic acid; D010072:Oxamic Acid