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The Blasticidin S Biosynthesis Gene Cluster from Streptomyces griseochromogenes : Sequence Analysis, Organization, and Initial Characterization
Author(s) -
Cone Martha C.,
Yin Xihou,
Grochowski Laura L.,
Parker Morgan R.,
Zabriskie T. Mark
Publication year - 2003
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.200300583
Subject(s) - gene cluster , biosynthesis , cytidine , biochemistry , biology , gene , streptomyces , nucleic acid sequence , chemistry , genetics , enzyme , bacteria
Blasticidin S is a potent antifungal and cytotoxic peptidyl nucleoside antibiotic from Streptomyces griseochromogenes. The mixed biosynthesis of the compound is evident from the three distinct structural components: a cytosine base, an amino deoxyglucuronic acid, and N ‐methyl β ‐arginine. The blasticidin S biosynthesis gene cluster was cloned from S. griseochromogenes and the pathway heterologously expressed in S. lividans from a cosmid harboring a 36.7‐kb fragment of S. griseochromogenes DNA. The complete DNA sequence of this insert has now been determined and evidence suggests a contiguous 20‐kb section defines the blasticidin S biosynthesis cluster. The predicted functions of several open reading frames are consistent with the expected biochemistry and include an arginine 2,3‐aminomutase, a cytosylglucuronic acid synthase, and a guanidino N ‐methyltransferase. Insight into other steps in the assembly of blasticidin S was evident from sequence homology with proteins of known function and heterologous expression of fragments of the cluster. Additionally, the gene that directs the production of free cytosine , blsM, was subcloned and expressed in Escherichia coli. Characterization of BlsM revealed that cytidine monophosphate serves as the precursor to cytosine.