A multifunctional polyketide-peptide synthetase essential for albicidin biosynthesis in Xanthomonas albilineans.
Albicidins, a family of potent antibiotics and phytotoxins produced by the sugarcane leaf scald pathogen Xanthomonas albilineans, inhibit DNA replication in bacteria and plastids. A gene located by Tn5-tagging was confirmed by complementation to participate in albicidin biosynthesis. The gene (xabB) encodes a large protein (predicted M:(r) 525695), with a modular architecture indicative of a multifunctional polyketide synthase (PKS) linked to a non-ribosomal peptide synthetase (NRPS). At 4801 amino acids in length, XabB is the largest reported PKS-NRPS. Twelve catalytic domains in this multifunctional enzyme are arranged in the order N terminus-acyl-CoA ligase (AL)-acyl carrier protein (ACP)-beta-ketoacyl synthase (KS)-beta-ketoacyl reductase (KR)-ACP-ACP-KS-peptidyl carrier protein (PCP)-condensation (C)-adenylation-PCP-C. The modular architecture of XabB indicates likely steps in albicidin biosynthesis and approaches to enhance antibiotic yield. The novel pattern of domains, in comparison with known PKS-NRPS enzymes for antibiotic production, also contributes to the knowledge base for rational design of enzymes producing novel antibiotics.
Department of Botany, The University of Queensland, Brisbane 4072, Australia1.
Guozhong
G
Huang
Institute of Molecular Agrobiology, The National University of Singapore, Singapore1176042.|Department of Botany, The University of Queensland, Brisbane 4072, Australia1.
Lianhui
L
Zhang
Department of Botany, The University of Queensland, Brisbane 4072, Australia1.
Robert G
RG
Birch
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001483:Base Sequence; D003001:Cloning, Molecular; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009930:Organic Chemicals; D010453:Peptide Synthases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014974:Xanthomonas / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development
D000900:Anti-Bacterial Agents; D009097:Multienzyme Complexes; D009930:Organic Chemicals; C046156:albicidin; D010453:Peptide Synthases