The gene lmbB2 of the lincomycin biosynthetic gene cluster of Streptomyces lincolnensis ATCC 25466 was shown to code for an unusual tyrosine hydroxylating enzyme involved in the biosynthetic pathway of this clinically important antibiotic. LmbB2 was expressed in Escherichia coli, purified near to homogeneity and shown to convert tyrosine to 3,4-dihydroxyphenylalanine (DOPA). In contrast to the well-known tyrosine hydroxylases (EC 1.14.16.2) and tyrosinases (EC 1.14.18.1), LmbB2 was identified as a heme protein. Mass spectrometry and Soret band-excited Raman spectroscopy of LmbB2 showed that LmbB2 contains heme b as prosthetic group. The CO-reduced differential absorption spectra of LmbB2 showed that the coordination of Fe was different from that of cytochrome P450 enzymes. LmbB2 exhibits sequence similarity to Orf13 of the anthramycin biosynthetic gene cluster, which has recently been classified as a heme peroxidase. Tyrosine hydroxylating activity of LmbB2 yielding DOPA in the presence of (6R)-5,6,7,8-tetrahydro-L-biopterin (BH4) was also observed. Reaction mechanism of this unique heme peroxidases family is discussed. Also, tyrosine hydroxylation was confirmed as the first step of the amino acid branch of the lincomycin biosynthesis.
- MeSH
- antibakteriální látky biosyntéza MeSH
- bakteriální proteiny genetika metabolismus MeSH
- cirkulární dichroismus MeSH
- dihydroxyfenylalanin metabolismus MeSH
- Escherichia coli enzymologie genetika MeSH
- exprese genu MeSH
- hem chemie metabolismus MeSH
- hemoproteiny genetika metabolismus MeSH
- hydroxylace MeSH
- linkomycin biosyntéza MeSH
- multigenová rodina MeSH
- rekombinantní proteiny genetika metabolismus MeSH
- Streptomyces enzymologie genetika MeSH
- tyrosin-3-monooxygenasa genetika metabolismus MeSH
- tyrosin metabolismus MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- železo chemie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- dihydroxyfenylalanin metabolismus MeSH
- fenylacetáty moč MeSH
- lidé MeSH
- melanom klasifikace moč MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- srovnávací studie MeSH
- MeSH
- dihydroxyfenylalanin metabolismus MeSH
- kyseliny sialové krev MeSH
- lidé MeSH
- melanocyty metabolismus MeSH
- melanom krev moč MeSH
- prognóza MeSH
- Check Tag
- lidé MeSH
Acta dermato-venereologica, ISSN 0365-8341 ; suppl. 126
12 s. : tab., grafy ; 26 cm
