Type II thioesterase from Streptomyces coelicolor A3(2).
Type I polyketide synthases (PKSs) are complexes of large, multimodular enzymes that catalyse biosynthesis of polyketide compounds via repetitive reaction sequences, during which each step is catalysed by a separate enzymic domain. Many type I PKSs, and also non-ribosomal peptide synthetase clusters, contain additional thioesterase genes located adjacent to PKS genes. These are discrete proteins called type II thioesterases (TE IIs) to distinguish them from chain-terminating thioesterase (TE I) domains that are usually fused to the terminal PKS module. A gene of a new TE II, scoT, associated with the cluster of putative type I PKS genes from Streptomyces coelicolor A3(2), was found. The deduced amino acid sequence of the gene product shows extensive similarity to other authentic thioesterase enzymes, including conservation of characteristic motifs and residues involved in catalysis. When expressed in the heterologous host Streptomyces fradiae, scoT successfully complemented the resident TE II gene (tylO), and, by restoring a significant level of macrolide production, proved to be catalytically equivalent to the TylO protein. S1 nuclease mapping of scoT revealed a single potential transcription start point with expression being switched on for a short period of time during a transition phase of growth.
Kotowska
Magdalena
M
Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114 Wroclaw, Poland1.
Pawlik
Krzysztof
K
Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114 Wroclaw, Poland1.
Butler
Andrew R
AR
Department of Biochemistry, University of Leicester, Leicester LE1 7RH, UK2.
Cundliffe
Eric
E
Department of Biochemistry, University of Leicester, Leicester LE1 7RH, UK2.
Takano
Eriko
E
Department of Molecular Microbiology, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK3.
Kuczek
Katarzyna
K
Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114 Wroclaw, Poland1.
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000096:biosynthesis; D003001:Cloning, Molecular; D064429:Fatty Acid Synthases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D005816:Genetic Complementation Test; D018942:Macrolides; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D013379:Substrate Specificity; D013869:Thiolester Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic
D000900:Anti-Bacterial Agents; D018942:Macrolides; D009097:Multienzyme Complexes; D064429:Fatty Acid Synthases; D013869:Thiolester Hydrolases; C022738:thioesterase II; D015719:Single-Strand Specific DNA and RNA Endonucleases