title: [Knockout and function analysis of pqqL gene in Escherichia coli].
abstract: OBJECTIVE
  To confirm the involvement of pqqL gene of Escherichia coli in PQQ biosynthesis, a pqqL deletion mutant of E. coli DH5alpha was constructed and investigated.
  
  
  METHODS
  pqqL and kan gene were cloned and a linear targeting fragment pqqL-kan-pqqL was constructed in vitro. Then pqqL gene was knocked out and DH5alphadeltapqqL mutant was constructed by Red homologous recombination. The PQQ biosynthesis was compared between the mutant and its parential strain by detection of bio-activity of sorbose dehydrogenase with DCIP method.
  
  
  RESULTS
  The DH5alphadeltapqqL deletion mutant was successfully constructed, and the result indicated that PQQ would be synthesized in pBCP162/DH5alphadeltapqqL and pMD19T Simple-pqqABCDE/DH5alpha, but not in pMD19T Simple-pqqABCDE/DH5alphadeltapqqL.
  
  
  CONCLUSIONS
  The function of pqqL gene in Escherichia coli is the same to that of pqqF gene.
authors.affiliation: Institute of Biotechnology, Academy of Military Medical Sciences, Beijing 100071, China. xiongxianghua@sina.com
authors.forename: Xianghua
authors.initials: X
authors.lastname: Xiong
authors.forename: Lu
authors.initials: L
authors.lastname: Yang
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Han
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wang
authors.forename: Weicai
authors.initials: W
authors.lastname: Zhang
mesh_terms: D004926:Escherichia coli / Q000235:genetics*; D055786:Gene Knockout Techniques / Q000379:methods*; D005798:Genes, Bacterial / Q000502:physiology*; D005822:Genetic Vectors; D009097:Multienzyme Complexes / Q000235:genetics* / Q000378:metabolism; D045542:PQQ Cofactor / Q000096:biosynthesis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011995:Recombination, Genetic
chemical_list: D009097:Multienzyme Complexes; C076608:pyrroloquinoline quinone synthase complex; D045542:PQQ Cofactor