Enzymatic generation of the antimetabolite gamma,gamma-dichloroaminobutyrate by NRPS and mononuclear iron halogenase action in a streptomycete.
Four adjacent open reading frames, cytC1-C4, were cloned from a cytotrienin-producing strain of a Streptomyces sp. by using primers derived from the conserved region of a gene encoding a nonheme iron halogenase, CmaB, in coronamic acid biosynthesis. CytC1-3 were active after expression in Escherichia coli, and CytC4 was active after expression in Pseudomonas putida. CytC1, a relatively promiscuous adenylation enzyme, installs the aminoacyl moieties on the phosphopantetheinyl arm of the holo carrier protein CytC2. CytC3 is a nonheme iron halogenase that will generate both gamma-chloro- and gamma,gamma-dichloroaminobutyryl-S-CytC2 from aminobutyryl-S-CytC2. CytC4, a thioesterase, hydrolytically releases the dichloroaminobutyrate, a known streptomycete antibiotic. Thus, this short four-protein pathway is likely the biosynthetic source of this amino acid antimetabolite. This four-enzyme system analogously converts the proS-methyl group of valine to the dichloromethyl product regio- and stereospecifically.
Ueki
Masashi
M
Antibiotics Laboratory, RIKEN Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Galonić
Danica P
DP
Vaillancourt
Frédéric H
FH
Garneau-Tsodikova
Sylvie
S
Yeh
Ellen
E
Vosburg
David A
DA
Schroeder
Frank C
FC
Osada
Hiroyuki
H
Walsh
Christopher T
CT
D000963:Antimetabolites / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002087:Butyrates / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000378:metabolism; D005810:Multigene Family; D010453:Peptide Synthases / Q000378:metabolism; D016958:Pseudomonas putida / Q000378:metabolism; D013302:Streptomyces / Q000378:metabolism*
D000963:Antimetabolites; D001426:Bacterial Proteins; D002087:Butyrates; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase