Sequencing and mutagenesis of genes from the erythromycin biosynthetic gene cluster of Saccharopolyspora erythraea that are involved in L-mycarose and D-desosamine production.
The nucleotide sequence on both sides of the eryA polyketide synthase genes of the erythromycin-producing bacterium Saccharopolyspora erythraea reveals the presence of ten genes that are involved in L-mycarose (eryB) and D-desosamine (eryC) biosynthesis or attachment. Mutant strains carrying targeted lesions in eight of these genes indicate that three (eryBIV, eryBV and eryBVI) act in L-mycarose biosynthesis or attachment, while the other five (eryCII, eryCIII, eryCIV, eryCV and eryCVI) are devoted to D-desosamine biosynthesis or attachment. The remaining two genes (eryBII and eryBVII) appear to function in L-mycarose biosynthesis based on computer analysis and earlier genetic data. Three of these genes, eryBII, eryCIII and eryCII, lie between the eryAIII and eryG genes on one side of the polyketide synthase genes, while the remaining seven, eryBIV, eryBV, eryCVI, eryBVI, eryCIV, eryCV and eryBVII lie upstream of the eryAI gene on the other side of the gene cluster. The deduced products of these genes show similarities to: aldohexose 4-ketoreductases (eryBIV), aldoketo reductases (eryBII), aldohexose 5-epimerases (eryBVII), the dnmT gene of the daunomycin biosynthetic pathway of Streptomyces peucetius (eryBVI), glycosyltransferases (eryBV and eryCIII), the AscC 3,4-dehydratase from the ascarylose biosynthetic pathway of Yersinia pseudotuberculosis (eryCIV), and mammalian N-methyltransferases (eryCVI). The eryCII gene resembles a cytochrome P450, but lacks the conserved cysteine residue responsible for coordination of the haem iron, while the eryCV gene displays no meaningful similarity to other known sequences. From the predicted function of these and other known eryB and eryC genes, pathways for the biosynthesis of L-mycarose and D-desosamine have been deduced.
Summers
Richard G
RG
Antibacterial Discovery Research Division, Abbott Laboratories, D-47P AP9A, 100 Abbott Park Road, Abbott Park, IL 60064, USA.
Donadio
Stefano
S
Antibacterial Discovery Research Division, Abbott Laboratories, D-47P AP9A, 100 Abbott Park Road, Abbott Park, IL 60064, USA.
Staver
Michael J
MJ
Antibacterial Discovery Research Division, Abbott Laboratories, D-47P AP9A, 100 Abbott Park Road, Abbott Park, IL 60064, USA.
Wendt-Pienkowski
Evelyn
E
School of Pharmacy, University of Wisconsin, Madison, WI 53706, USA.
Hutchinson
C Richard
CR
School of Pharmacy, University of Wisconsin, Madison, WI 53706, USA.
Katz
Leonard
L
Antibacterial Discovery Research Division, Abbott Laboratories, D-47P AP9A, 100 Abbott Park Road, Abbott Park, IL 60064, USA.
D000595:Amino Acid Sequence; D000606:Amino Sugars / Q000096:biosynthesis; D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000737:chemistry; D004798:Enzymes / Q000235:genetics; D004917:Erythromycin / Q000031:analogs & derivatives / Q000096:biosynthesis* / Q000737:chemistry; D005798:Genes, Bacterial; D006601:Hexoses / Q000096:biosynthesis; D008969:Molecular Sequence Data; D005810:Multigene Family; D016296:Mutagenesis; D016366:Open Reading Frames; D016930:Saccharopolyspora / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D000606:Amino Sugars; D000900:Anti-Bacterial Agents; D004798:Enzymes; D006601:Hexoses; C045835:mycarose; C110125:desosamine; D004917:Erythromycin