Functional expression of genes involved in the biosynthesis of the novel polyketide chain extension unit, methoxymalonyl-acyl carrier protein, and engineered biosynthesis of 2-desmethyl-2-methoxy-6-deoxyerythronolide B.
A subcluster of five genes, asm13-17, from the ansamitocin biosynthetic gene cluster of Actinosynnema pretiosum was coexpressed in Streptomyces lividans with the genes encoding the 6-deoxyerythronolide B (6-DEB) synthase from Saccharopolyspora erythraea, in which the methylmalonate-specifying AT6 domain had been replaced by the methoxymalonate-specifying AT8 domain from the FK520 cluster of Streptomyces hygroscopicus. The engineered strain produced the predicted product, 2-desmethyl-2-methoxy-DEB, instead of 6-DEB and 2-desmethyl-6-DEB, which were formed in the absence of the asm13-17 cassette, indicating that asm13-17 are sufficient for synthesis of this unusual chain extension unit. Deletion of asm17, encoding a methyltransferase, from the cassette gave 6-DEB instead of its hydroxy analogue, indicating that methylation of the extender unit is required for its incorporation.
Kato
Yasuo
Y
Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700, USA.
Bai
Linquan
L
Xue
Qun
Q
Revill
W Peter
WP
Yu
Tin-Wein
TW
Floss
Heinz G
HG
D000213:Acyl Carrier Protein / Q000096:biosynthesis* / Q000235:genetics*; D004917:Erythromycin / Q000031:analogs & derivatives* / Q000096:biosynthesis; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005818:Genetic Engineering; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism
C460119:2-desmethyl-2-methoxy-6-deoxyerythronolide B; D000213:Acyl Carrier Protein; D009097:Multienzyme Complexes; D004917:Erythromycin