Genes encoding enzymes responsible for biosynthesis of L-lyxose and attachment of eurekanate during avilamycin biosynthesis.

The oligosaccharide antibiotic avilamycin A is composed of a polyketide-derived dichloroisoeverninic acid moiety attached to a heptasaccharide chain consisting of six hexoses and one unusual pentose moiety. We describe the generation of mutant strains of the avilamycin producer defective in different sugar biosynthetic genes. Inactivation of two genes (aviD and aviE2) resulted in the breakdown of the avilamycin biosynthesis.

Genes involved in formation and attachment of a two-carbon chain as a component of eurekanate, a branched-chain sugar moiety of avilamycin A.

Eurekanate belongs to the important class of branched-chain carbohydrates present in a wide variety of natural sources. It is a component of avilamycin A, a potent inhibitor of bacterial protein synthesis targeting the 50S ribosomal subunit. The present work provides experimental proof for the function of two genes of the avilamycin biosynthetic gene cluster, aviB1 and aviO2, that are both involved in avilamycin structure modification.

Novel avilamycin derivatives with improved polarity generated by targeted gene disruption.

The oligosaccharide antibiotics avilamycin A and C are produced by Streptomyces viridochromogenes Tu57. Both consist of a heptasaccharide chain, which is attached to a polyketide-derived dichloroisoeverninic acid moiety. They show excellent antibiotic activity against Gram-positive bacteria.

The avilamycin resistance determinants AviRa and AviRb methylate 23S rRNA at the guanosine 2535 base and the uridine 2479 ribose.

Avilamycin is an orthosomycin antibiotic that has shown considerable potential for clinical use, although it is presently used as a growth promoter in animal feed. Avilamycin inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. The ribosomes of the producer strain, Streptomyces viridochromogenes Tü57, are protected from the drug by the action of three resistance factors located in the avilamycin biosynthetic gene cluster.