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
• Názvy látek
• antibakteriální látky MeSH
• bakteriální proteiny MeSH
• dihydroxyfenylalanin MeSH
• hem MeSH
• hemoproteiny MeSH
• linkomycin MeSH
• rekombinantní proteiny MeSH
• tyrosin-3-monooxygenasa MeSH
• tyrosin MeSH
• železo MeSH