title: l-3,4-Dihydroxyphenyl alanine-extradiol cleavage is followed by intramolecular cyclization in lincomycin biosynthesis.
abstract: The LmbB1 protein, participating in the biosynthesis of lincomycin, was heterologously expressed in Escherichia coli, purified in its active form, and characterized as a dimer of identical subunits. Methods for purification and analysis of the LmbB1 reaction product were developed. Molecular mass and fragmentation pattern of the product revealed by capillary electrophoresis-mass spectrometry were in agreement with its proposed structure, 4-(3-carboxy-3-oxo-propenyl)-2,3-dihydro-1H-pyrrole-2-carboxylic acid. The LmbB1 is therefore a dioxygenase catalysing the 2,3-extradiol cleavage of the l-3,4-dihydroxyphenyl alanine aromatic ring. The final LmbB1 reaction product, a unique compound found in biosynthesis of lincomycin and expected in anthramycins, arises through subsequent cyclization of the primary cleavage product, 2,3-secodopa. A possible role of LmbB1 in 2,3-secodopa cyclization and alternative ways of the cyclization in the formation of biosynthetically related compounds, muscaflavin and stizolobinic acid, are discussed.
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská, Praha, Czech Republic. jinov@biomed.cas.cz
authors.forename: Jitka
authors.initials: J
authors.lastname: Novotná
authors.forename: Ales
authors.initials: A
authors.lastname: Honzátko
authors.forename: Petr
authors.initials: P
authors.lastname: Bednár
authors.forename: Jan
authors.initials: J
authors.lastname: Kopecký
authors.forename: Jirí
authors.initials: J
authors.lastname: Janata
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Spízek
mesh_terms: D002852:Chromatography, Ion Exchange; D003500:Cyclization; D004295:Dihydroxyphenylalanine / Q000378:metabolism*; D019075:Electrophoresis, Capillary; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism*; D008034:Lincomycin / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D013058:Mass Spectrometry; D015394:Molecular Structure; D013302:Streptomyces / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D004958:Estradiol; D004295:Dihydroxyphenylalanine; D008034:Lincomycin