Mutational Biosynthesis of New Antibiotics

Daum, Sol J.; Lemke, Johannes R.

doi:10.1146/annurev.mi.33.100179.001325

Cited by 61 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This indicates that at position 3 of the cyclitol ring, the aminotransferase can tolerate a hydroxyl group in either the axial or equatorial position. It would be of interest to determine whether epi-inosose can be utilized by the rest of the enzymes of 2-deoxystreptamine biosynthesis, since idiotrophs of S. fradiae incorporate 2-epi-streptamine and an idiotroph ofMicromonospora inyoensis incorporates 5-epi-2-deoxystreptamine into antibiotic analogs (8,23).…”

Section: Discussionmentioning

confidence: 99%

Reactions catalyzed by purified L-glutamine: keto-scyllo-inositol aminotransferase, an enzyme required for biosynthesis of aminocyclitol antibiotics

Lucher

Chen

Walker

1989

Antimicrob Agents Chemother

View full text Add to dashboard Cite

Dialyzed extracts of the gentamicin producer Micromonospora purpurea catalyze reactions which represent transaminations proposed for 2-deoxystreptamine biosynthesis. To determine whether these transaminations were catalyzed by a single aminotransferase or by multiple enzymes, we purified and characterized an L-glutamine:keto-scyllo-inositol aminotransferase from M. purpurea. This enzyme was purified 130-to 150-fold from late-log-phase mycelia of both wild-type M. purpurea and a 2-deoxystreptamine-less idiotroph. The cofactor pyridoxal phosphate was found to be tightly bound to the enzyme, and spectral analysis demonstrated its participation in the transamination reactions of this enzyme. The major physiological amino donor for the enzyme appears to be L-glutamine; the keto acid product derived from glutamine was characterized as 2-ketoglutaramate, indicating that the alpha amino group of glutamine participates in the transamination. We found that crude extracts contained omega-amidase activity, which may render transaminations with glutamine irreversible in vivo. The substrate specificity of the aminotransferase was shown to be restricted to deoxycyclitols, monoaminocyclitols, and diaminocyclitols, glutamine, and 2-ketoglutaramate, which contrasts with the broader substrate specificity of mammalian glutamine aminotransferase. The appearance of the enzyme in late-log phase, coupled with its narrow substrate specificity, indicates that it participates predominantly in 2-deoxystreptamine biosynthesis rather than in general metabolism. The enzyme catalyzes reactions which represent both transamination steps of 2-deoxystreptamine biosynthesis. Although copurification of two aminotransferases cannot be ruled out, our data are consistent with the participation of a single aminotransferase in the formation of both amino groups of 2-deoxystreptamine during biosynthesis by M. purpurea. We propose that this aminotransferase participates in a key initial step in the biosynthesis of most aminocyclitol antibiotics.2-Deoxystreptamine is a component of numerous clinically important antibiotics such as gentamicin, neomycin, tobramycin, amikacin, and hygromycin, while streptamine is known to occur naturally in place of 2-deoxystreptamine in at least one member (SS-56C) of the destomycin group (for reviews, see references 19 and 21). A pathway for 2-deoxystreptamine biosynthesis has been proposed (Fig. 1) on the basis of mutasynthesis and isotopic competition studies (9, 13) and in vitro enzymatic studies (5). The two aminotransferase steps of this pathway may be analogous to the two transaminations which occur in the biosynthesis of the streptidine moiety of streptomycin (27). These reactions in streptidine biosynthesis are catalyzed by separate enzymes; L-glutamine:keto-scyllo-inositol aminotransferase (glutamine-scyllo-inosose aminotransferase; EC 2.6.1.50) catalyzes the first transamination reaction (26). This enzymatic activity has also been detected in extracts of actinomycetes that produce bluensomycin (26) and the 2-deoxys...

show abstract

Section: Discussionmentioning

confidence: 99%

Reactions catalyzed by purified L-glutamine: keto-scyllo-inositol aminotransferase, an enzyme required for biosynthesis of aminocyclitol antibiotics

Lucher

Chen

Walker

1989

Antimicrob Agents Chemother

View full text Add to dashboard Cite

show abstract

“…This feature allowed to develop amikacin as a commercial semisynthetic antibiotic for the treatment of resistant bacteria [5]. Biosynthetic approach appears to be an alternative to this end [6,7].…”

Section: Introductionmentioning

confidence: 99%

Extended Sequence and Functional Analysis of the Butirosin Biosynthetic Gene Cluster in Bacillus circulans SANK 72073

et al. 2005

View full text Add to dashboard Cite

Butirosin produced by Bacillus circulans is among the clinically important 2-deoxystreptamine containing aminoglycoside antibiotics and its unique structure is found in (S )-4-amino-2-hydroxyburyric acid substituted at C-1 of 2-deoxystreptamine. Recently, the key part of the butirosin biosynthetic gene cluster has been identified from Bacillus circulans SANK 72073, however the whole gene for the biosynthesis awaited for identification. In the present study, we undertook extended analysis of the butirosin biosynthetic gene cluster and found nine additional open reading flames (ORFs), btrQ, btrR1, btrR2, btrT, btrU, btrV, btrW, btrX and orf1 in the cluster. In addition, we constructed disruption mutants of btrR1 and btrP-V, and found that the btr genes (ca. 24 Kb) between btrR1 and btrP-V are at least required for the butirosin biosynthesis.

show abstract

“…The reactions are generalized here for streptamine synthesis as might occur in the synthesis of the SS-56C antibiotic (7) or 2-hydroxygentamicin by Daum's idiotroph (5,6). Dehydrogenases like those in reactions c, g, and h of Fig.…”

Section: Fig 2 Enzymatic Reactions Involved In Biosynthesis From Mymentioning

confidence: 99%

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

Walker

1995

J Bacteriol

View full text Add to dashboard Cite

Mutational Biosynthesis of New Antibiotics

Cited by 61 publications

References 0 publications

Reactions catalyzed by purified L-glutamine: keto-scyllo-inositol aminotransferase, an enzyme required for biosynthesis of aminocyclitol antibiotics

Reactions catalyzed by purified L-glutamine: keto-scyllo-inositol aminotransferase, an enzyme required for biosynthesis of aminocyclitol antibiotics

Extended Sequence and Functional Analysis of the Butirosin Biosynthetic Gene Cluster in Bacillus circulans SANK 72073

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

Contact Info

Product

Resources

About