Identification of the biosynthetic gene cluster for 3-methylarginine, a toxin produced by Pseudomonas syringae pv. syringae 22d/93.
The epiphyte Pseudomonas syringae pv. syringae 22d/93 (Pss22d) produces the rare amino acid 3-methylarginine (MeArg), which is highly active against the closely related soybean pathogen Pseudomonas syringae pv. glycinea. Since these pathogens compete for the same habitat, Pss22d is a promising candidate for biocontrol of P. syringae pv. glycinea. The MeArg biosynthesis gene cluster codes for the S-adenosylmethionine (SAM)-dependent methyltransferase MrsA, the putative aminotransferase MrsB, and the amino acid exporter MrsC. Transfer of the whole gene cluster into Escherichia coli resulted in heterologous production of MeArg. The methyltransferase MrsA was overexpressed in E. coli as a His-tagged protein and functionally characterized (K(m), 7 mM; k(cat), 85 min(-1)). The highly selective methyltransferase MrsA transfers the methyl group from SAM into 5-guanidino-2-oxo-pentanoic acid to yield 5-guanidino-3-methyl-2-oxo-pentanoic acid, which then only needs to be transaminated to result in the antibiotic MeArg.
Braun
S D
SD
Institute of Microbiology, Microbial Phytopathology, University of Jena, Neugasse 25, 07743 Jena, Germany.
Hofmann
J
J
Wensing
A
A
Ullrich
M S
MS
Weingart
H
H
Völksch
B
B
Spiteller
D
D
D001120:Arginine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism; D001427:Bacterial Toxins / Q000096:biosynthesis*; D053898:Biosynthetic Pathways / Q000235:genetics*; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D044224:Pseudomonas syringae / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013025:Glycine max / Q000382:microbiology
C532871:3-methylarginine; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D011994:Recombinant Proteins; D001120:Arginine