scholarly journals Enhancement of the Diversity of Polyoxins by a Thymine-7-Hydroxylase Homolog outside the Polyoxin Biosynthesis Gene Cluster

2010 ◽  
Vol 76 (21) ◽  
pp. 7343-7347 ◽  
Author(s):  
Changming Zhao ◽  
Tingting Huang ◽  
Wenqing Chen ◽  
Zixin Deng
Keyword(s):  
Gene Cluster ◽  
Carbon Skeleton ◽  
Open Reading Frame ◽  
Streptomyces Avermitilis ◽  
Biosynthesis Gene Cluster ◽  
Reading Frame ◽  
Biosynthesis Gene ◽  
Pyrimidine Moiety

ABSTRACT Polyoxins consist of 14 structurally variable components which differentiate at three branch sites of the carbon skeleton. Open reading frame (ORF) SAV_4805 of Streptomyces avermitilis, showing similarity to thymine-7-hydroxylase, was proved to enhance the diversity of polyoxins at the C-5 site of the 1-(5′-amino-5′-deoxy-β-d-allofuranuronosyl) pyrimidine moiety.

scholarly journals Isolation and Characterization of Canthaxanthin Biosynthesis Genes from the Photosynthetic Bacterium Bradyrhizobiumsp. Strain ORS278

2000 ◽  
Vol 182 (13) ◽  
pp. 3850-3853 ◽  
Author(s):  
Laure Hannibal ◽  
Jean Lorquin ◽  
Nicolas Angles D'Ortoli ◽  
Nelly Garcia ◽  
Clemence Chaintreuil ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Photosynthetic Bacterium ◽  
Carotenoid Biosynthesis ◽  
Open Reading Frame ◽  
Biosynthesis Gene Cluster ◽  
Reading Frame ◽  
Functional Assignment ◽  
Isolation And Characterization ◽  
Biosynthesis Gene

ABSTRACT A carotenoid biosynthesis gene cluster involved in canthaxanthin production was isolated from the photosyntheticBradyrhizobium sp. strain ORS278. This cluster includes five genes identified as crtE, crtY,crtI, crtB, and crtW that are organized in at least two operons. The functional assignment of each open reading frame was confirmed by complementation studies.

scholarly journals HypC, the Anthrone Oxidase Involved in Aflatoxin Biosynthesis

2010 ◽  
Vol 76 (10) ◽  
pp. 3374-3377 ◽  
Author(s):  
Kenneth C. Ehrlich ◽  
Ping Li ◽  
Leslie Scharfenstein ◽  
Perng-Kuang Chang
Keyword(s):  
Enzyme Activity ◽  
Gene Cluster ◽  
Gene Disruption ◽  
Open Reading Frame ◽  
Aflatoxin Biosynthesis ◽  
Biosynthesis Gene Cluster ◽  
Reading Frame ◽  
Biosynthesis Gene ◽  
Norsolorinic Acid

ABSTRACT On the basis of gene disruption and enzyme activity, hypC, an open reading frame in the region between the pksA (aflC) and nor-1 (aflD) genes in the aflatoxin biosynthesis gene cluster, encodes a 17-kDa oxidase that converts norsolorinic acid anthrone to norsolorinic acid.

scholarly journals X-ray crystal structure of ornithine acetyltransferase from the clavulanic acid biosynthesis gene cluster

2005 ◽  
Vol 385 (2) ◽  
pp. 565-573 ◽  
Author(s):  
Jonathan M. ELKINS ◽  
Nadia J. KERSHAW ◽  
Christopher J. SCHOFIELD
Keyword(s):  
Crystal Structure ◽  
Clavulanic Acid ◽  
Gene Cluster ◽  
Acid Biosynthesis ◽  
Biosynthesis Gene Cluster ◽  
Reading Frame ◽  
X Ray ◽  
Orf6 Gene ◽  
Biosynthesis Gene ◽  
Acetyl Transfer

The orf6 gene from the clavulanic acid biosynthesis gene cluster encodes an OAT (ornithine acetyltransferase). Similar to other OATs the enzyme has been shown to catalyse the reversible transfer of an acetyl group from N-acetylornithine to glutamate. OATs are Ntn (N-terminal nucleophile) enzymes, but are distinct from the better-characterized Ntn hydrolase enzymes as they catalyse acetyl transfer rather than a hydrolysis reaction. In the present study, we describe the X-ray crystal structure of the OAT, corresponding to the orf6 gene product, to 2.8 Å (1 Å=0.1 nm) resolution. The larger domain of the structure consists of an αββα sandwich as in the structures of Ntn hydrolase enzymes. However, differences in the connectivity reveal that OATs belong to a structural family different from that of other structurally characterized Ntn enzymes, with one exception: unexpectedly, the αββα sandwich of ORF6 (where ORF stands for open reading frame) displays the same fold as an DmpA (L-aminopeptidase D-ala-esterase/amidase from Ochrobactrum anthropi), and so the OATs and DmpA form a new structural subfamily of Ntn enzymes. The structure reveals an α2β2-heterotetrameric oligomerization state in which the intermolecular interface partly defines the active site. Models of the enzyme–substrate complexes suggest a probable oxyanion stabilization mechanism as well as providing insight into how the enzyme binds its two differently charged substrates.

scholarly journals Characterization of the Biosynthesis Gene Cluster for the Pyrrole Polyether Antibiotic Calcimycin (A23187) inStreptomyces chartreusisNRRL 3882

2010 ◽  
Vol 55 (3) ◽  
pp. 974-982 ◽  
Author(s):  
Qiulin Wu ◽  
Jingdan Liang ◽  
Shuangjun Lin ◽  
Xiufen Zhou ◽  
Linquan Bai ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Mutational Analysis ◽  
Divalent Cations ◽  
Biological Effects ◽  
Biosynthetic Gene Cluster ◽  
Type I ◽  
Biosynthesis Gene Cluster ◽  
Biosynthesis Gene ◽  
Hydroxyanthranilic Acid

ABSTRACTThe pyrrole polyether antibiotic calcimycin (A23187) is a rare ionophore that is specific for divalent cations. It is widely used as a biochemical and pharmacological tool because of its multiple, unique biological effects. Here we report on the cloning, sequencing, and mutational analysis of the 64-kb biosynthetic gene cluster fromStreptomyces chartreusisNRRL 3882. Gene replacements confirmed the identity of the gene cluster, andin silicoanalysis of the DNA sequence revealed 27 potential genes, including 3 genes for the biosynthesis of the α-ketopyrrole moiety, 5 genes that encode modular type I polyketide synthases for the biosynthesis of the spiroketal ring, 4 genes for the biosynthesis of 3-hydroxyanthranilic acid, anN-methyltransferase tailoring gene, a resistance gene, a type II thioesterase gene, 3 regulatory genes, 4 genes with other functions, and 5 genes of unknown function. We propose a pathway for the biosynthesis of calcimycin and assign the genes to the biosynthesis steps. Our findings set the stage for producing much desired calcimycin derivatives using genetic modification instead of chemical synthesis.

scholarly journals Characterization of the Amicetin Biosynthesis Gene Cluster from Streptomyces vinaceusdrappus NRRL 2363 Implicates Two Alternative Strategies for Amide Bond Formation

2012 ◽  
Vol 78 (7) ◽  
pp. 2393-2401 ◽  
Author(s):  
Gaiyun Zhang ◽  
Haibo Zhang ◽  
Sumei Li ◽  
Ji Xiao ◽  
Guangtao Zhang ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Acyl Carrier Protein ◽  
Bond Formation ◽  
Antiviral Agent ◽  
Amide Bond ◽  
Biosynthesis Gene Cluster ◽  
Alternative Strategies ◽  
Content Type ◽  
Amide Bond Formation ◽  
Biosynthesis Gene

ABSTRACTAmicetin, an antibacterial and antiviral agent, belongs to a group of disaccharide nucleoside antibiotics featuring an α-(1→4)-glycoside bond in the disaccharide moiety. In this study, the amicetin biosynthesis gene cluster was cloned fromStreptomyces vinaceusdrappusNRRL 2363 and localized on a 37-kb contiguous DNA region. Heterologous expression of the amicetin biosynthesis gene cluster inStreptomyces lividansTK64 resulted in the production of amicetin and its analogues, thereby confirming the identity of theamigene cluster.In silicosequence analysis revealed that 21 genes were putatively involved in amicetin biosynthesis, including 3 for regulation and transportation, 10 for disaccharide biosynthesis, and 8 for the formation of the amicetin skeleton by the linkage of cytosine,p-aminobenzoic acid (PABA), and the terminal (+)-α-methylserine moieties. The inactivation of the benzoate coenzyme A (benzoate-CoA) ligase geneamiLand theN-acetyltransferase geneamiFled to two mutants that accumulated the same two compounds, cytosamine and 4-acetamido-3-hydroxybenzoic acid. These data indicated that AmiF functioned as an amide synthethase to link cytosine and PABA. The inactivation ofamiR, encoding an acyl-CoA-acyl carrier protein transacylase, resulted in the production of plicacetin and norplicacetin, indicating AmiR to be responsible for attachment of the terminal methylserine moiety to form another amide bond. These findings implicated two alternative strategies for amide bond formation in amicetin biosynthesis.

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