title: Regions involved in fengycin synthetases enzyme complex formation.
abstract: BACKGROUND
  Fengycin is a lipopeptide antibiotic synthesized nonribosomally by five fengycin synthetases. These enzymes are linked in a specific order to form the complex. This study investigates how these enzymes interact in the complex and analyzes the regions in the enzymes that are critical to the interactions.
  
  
  METHODS
  Deletions were generated in the fengycin synthetases. The interaction of these mutant proteins with their partner enzymes in the complex was analyzed in vitro by a glutathione S-transferase (GST) or nickel pulldown assay.
  
  
  RESULTS
  The communication-mediating donor (COM-D) domains of the fengycin synthetases, when fused to GST, specifically pulled down their downstream partner enzymes in the GST-pulldown assays. The communication-mediating acceptor (COM-A) domains were required for binding between two partner enzymes, although the domains alone did not confer specificity of the binding to their upstream partner enzymes. This study found that the COM-A domain, the condensation domain, and a portion of the adenylation domain in fengycin synthetase B (FenB) were required for specific binding to fengycin synthetase A (FenA).
  
  
  CONCLUSIONS
  The interaction between the COM-D and COM-A domains in two partner enzymes is critical for nonribosomal peptide synthesis. The COM-A domain alone is insufficient for interacting with its upstream partner enzyme in the enzyme complex with specificity; a region that contains COM-A, condensation, and a portion of adenylation domains in the downstream partner enzyme is required.
authors: Department of Microbiology and Immunology, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors: Yu-Chieh
authors: YC
authors: Cheng
authors: Department of Microbiology and Immunology, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Microbiology and Immunology, Research Center for Bacterial Pathogenesis, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors: Wan-Ju
authors: WJ
authors: Ke
authors: Department of Microbiology and Immunology, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Medical Research and Development Chiayi Branch, Chang Gung Memorial Hospital, Chiayi, Taiwan. Electronic address: cgliu@mail.cgu.edu.tw.
authors: Shih-Tung
authors: ST
authors: Liu
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D055666:Lipopeptides / Q000096:biosynthesis*; D046908:Peptide Biosynthesis, Nucleic Acid-Independent / Q000502:physiology*; D010453:Peptide Synthases / Q000235:genetics* / Q000378:metabolism*; D011485:Protein Binding; D000072417:Protein Domains / Q000235:genetics; D025941:Protein Interaction Mapping; D017384:Sequence Deletion / Q000235:genetics
chemical_list: D055666:Lipopeptides; C049972:fengycin; D005982:Glutathione Transferase; D010453:Peptide Synthases; C110972:fengycin synthetase
keywords: communication-mediating donor and acceptor domain; fengycin synthetase; protein-protein interaction