Rachel Kreisberg-Zakarin

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Isopenicillin N synthase (IPNS) from Streptomyces jumonjinensis (M(r) 37,902) is a non-heme ferrous iron-containing enzyme that catalyzes the oxidative cyclization of the tripeptide delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine (ACV) to form isopenicillin N. Spectroscopic studies [reviewed in Cooper, R. D. (1993) Biomed. Chem. 1, 1-17] have led to a(More)
Isopenicillin N synthase (IPNS) is a non-heme ferrous iron-dependent oxygenase that catalyzes the ring closure of delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine (ACV) to form isopenicillin N. Spectroscopic studies and the crystal structure of IPNS show that the iron atom in the active species is coordinated to two histidine and one aspartic acid(More)
Isopenicillin N synthase is a key enzyme in the biosynthesis of penicillin and cephalosporin antibiotics, catalyzing the oxidative ring closure of δ-(L-α-aminoadipoyl)-L-cysteinyl-D-valine to form isopenicillin N. Recent advances in our understanding of the unique chemistry of this enzyme have come through the combined application of spectroscopic,(More)
Genes encoding two ribonucleotide reductases (RNRs) were identified in members of the genus Streptomyces. One gene, nrdJ, encoded an oligomeric protein comprising four identical subunits each with a molecular mass of approximately 108 kDa. The activity of this protein depended on the presence of 5'-deoxyadenosylcobalamine (coenzyme B12), establishing it as(More)
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