Identification of the biosynthetic gene cluster of A-500359s in Streptomyces griseus SANK60196

Abstract

A-500359s, produced by Streptomyces griseus SANK60196, are inhibitors of bacterial phospho-N-acetylmuramyl-pentapeptide translocase. They are composed of three distinct moieties: a 5¢-carbamoyl uridine, an unsaturated hexuronic acid and an aminocaprolactam. Two contiguous cosmids covering a 65-kb region of DNA and encoding 38 open reading frames (ORFs) putatively involved in the biosynthesis of A-500359s were identified. Reverse transcriptase PCR showed that most of the 38 ORFs are highly expressed during A-500359s production, but mutants that do not produce A-500359s did not express these same ORFs. Furthermore, orf21, encoding a putative aminoglycoside 3¢-phosphotransferase, was heterologously expressed in Escherichia coli and Streptomyces albus, yielding strains having selective resistance against A-500359B, suggesting that ORF21 phosphorylates the unsaturated hexuronic acid as a mechanism of self-resistance to A-500359s. In total, the data suggest that the cloned region is involved in the resistance, regulation and biosynthesis of A-500359s.

The Biosynthesis of Capuramycin-type Antibiotics

“…The biosynthetic gene cluster for 1 and 2 have been identified, and evidence for the involvement of 21 open reading frames (ORFs) was provided by gene expression profiling of the wild-type, 1-producing strain and several null mutants created by random chemical mutagenesis (24,25). Additional evidence that the correct gene cluster was identified was provided by functional assignment of genes involved in 2 biosynthesis: one (capP) encoding an ATP-dependent phosphotransferase that modifies the 3Љ-OH of the unsaturated ␣-D-mannopyranuronate as a mechanism of self-resistance (26) and the other (capW) encoding an L-ACL:2d transacylase (25).…”

Characterization of LipL as a Non-heme, Fe(II)-dependent α-Ketoglutarate:UMP Dioxygenase That Generates Uridine-5′-aldehyde during A-90289 Biosynthesis

“…1), this enzyme was an obvious candidate to catalyze an aldol-type condensation using uridine-5Ј-aldehyde as the "hydroxymethyl" donor in place of N 5 ,N 10 -methylene tetrahydrofolate. Rather unexpected was the uncovering of a homologous serine hydroxymethyltransferases within the biosynthetic gene clusters for the C6 nucleosides A-500359 (14) and A-503083 (15), which are characterized by a 5Ј-C-carbamoyl-uridine (Fig. 1).…”

Characterization of the Amicetin Biosynthesis Gene Cluster from Streptomyces vinaceusdrappus NRRL 2363 Implicates Two Alternative Strategies for Amide Bond Formation

“…The biosynthesis gene clusters for a number of pyrimidine nucleoside antibiotics have been elucidated, including nikkomycin (4,46), polyoxin (8), blasticidin S (13), A-500359s and A-503803s (25), caprazamycin (38), lipisidomycin (39) and its analogue A-90289 (24), pacidamycins (50,60), muraymycin (12), and tunicamycin (9). However, biosynthesis studies for the amicetin group of disaccharide nucleoside antibiotics are not yet available.…”