Enzymatic synthesis of aminocyclitol moieties of aminoglycoside antibiotics from inositol by Streptomyces spp.: detection of glutamine-aminocyclitol aminotransferase and diaminocyclitol aminotransferase activities in a spectinomycin producer.
Extracts of stationary-phase mycelia of the spectinomycin producer Streptomyces flavopersicus ATCC 19756 catalyzed inositol dehydrogenase, L-glutamine:inosose aminotransferase, 2-epi-streptamine:inosose aminotransferase, streptamine:inosose aminotransferase, N3-methyl-2-deoxystreptamine:inosose aminotransferase, and aminodeoxy-scyllo-inositol:inosose aminotransferase reactions, as detected with a new rapid assay procedure. These results suggest that one or both amino groups of the N1,N3-dimethyl-2-epi-streptamine moiety of spectinomycin are derived by transamination from the alpha-amino group of L-glutamine. An enzymatic procedure for distinguishing among N1- and N3-monomethyl diaminocyclitol derivatives and their diaminocyclitol biosynthetic precursors is described. A scheme showing key roles of glutamine-aminocyclitol aminotransferases in biosynthesis of major aminoglycoside antibiotics is presented.
Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77251.
J B
JB
Walker
D005973:Glutamine / Q000378:metabolism*; D007294:Inositol / Q000378:metabolism*; D012155:Reticulin / Q000096:biosynthesis; D000198:Spectinomycin / Q000096:biosynthesis*; D013302:Streptomyces / Q000378:metabolism*; D000637:Transaminases / Q000378:metabolism*
D012155:Reticulin; D005973:Glutamine; D007294:Inositol; D000198:Spectinomycin; D000637:Transaminases