Starter Unit Specificity of the Asukamycin “Upper” Chain Polyketide Synthase and the Branched-Chain Fatty Acid Synthase of Streptomyces nodosus subsp. asukaensis

Heterocycles ◽  
2006 ◽  
Vol 69 (1) ◽  
pp. 133 ◽  
Author(s):  
Heinz G. Floss ◽  
Yiding Hu
2000 ◽  
Vol 182 (2) ◽  
pp. 365-370 ◽  
Author(s):  
Keum-Hwa Choi ◽  
Richard J. Heath ◽  
Charles O. Rock

ABSTRACT A universal set of genes encodes the components of the dissociated, type II, fatty acid synthase system that is responsible for producing the multitude of fatty acid structures found in bacterial membranes. We examined the biochemical basis for the production of branched-chain fatty acids by gram-positive bacteria. Two genes that were predicted to encode homologs of the β-ketoacyl-acyl carrier protein synthase III of Escherichia coli (eFabH) were identified in theBacillus subtilis genome. Their protein products were expressed, purified, and biochemically characterized. Both B. subtilis FabH homologs, bFabH1 and bFabH2, carried out the initial condensation reaction of fatty acid biosynthesis with acetyl-coenzyme A (acetyl-CoA) as a primer, although they possessed lower specific activities than eFabH. bFabH1 and bFabH2 also utilized iso- and anteiso-branched-chain acyl-CoA primers as substrates. eFabH was not able to accept these CoA thioesters. Reconstitution of a complete round of fatty acid synthesis in vitro with purified E. coli proteins showed that eFabH was the only E. colienzyme incapable of using branched-chain substrates. Expression of either bFabH1 or bFabH2 in E. coli resulted in the appearance of a branched-chain 17-carbon fatty acid. Thus, the substrate specificity of FabH is an important determinant of branched-chain fatty acid production.


1991 ◽  
Vol 266 (36) ◽  
pp. 24670-24675 ◽  
Author(s):  
G. Vanhove ◽  
P.P. Van Veldhoven ◽  
F. Vanhoutte ◽  
G. Parmentier ◽  
H.J. Eyssen ◽  
...  

2016 ◽  
Vol 105 (1) ◽  
pp. 177-184 ◽  
Author(s):  
Kelly A Dingess ◽  
Christina J Valentine ◽  
Nicholas J Ollberding ◽  
Barbara S Davidson ◽  
Jessica G Woo ◽  
...  

2008 ◽  
Vol 148 (4) ◽  
pp. 1830-1846 ◽  
Author(s):  
Stephen P. Slocombe ◽  
Ines Schauvinhold ◽  
Ryan P. McQuinn ◽  
Katrin Besser ◽  
Nicholas A. Welsby ◽  
...  

1982 ◽  
Vol 152 (1) ◽  
pp. 246-254
Author(s):  
Caroline S. Harwood ◽  
Ercole Canale-Parola

Spirochete MA-2, which is anaerobic, ferments glucose, forming acetate as a major product. The spirochete also ferments (but does not utilize as growth substrates) small amounts of l -leucine, l -isoleucine, and l -valine, forming the branched-chain fatty acids isovalerate, 2-methylbutyrate, and isobutyrate, respectively, as end products. Energy generated through the fermentation of these amino acids is utilized to prolong cell survival under conditions of growth substrate starvation. A branched-chain fatty acid kinase and two acetate kinase isozymes were resolved from spirochete MA-2 cell extracts. Kinase activity was followed by measuring the formation of acyl phosphate from fatty acid and ATP. The branched-chain fatty acid kinase was active with isobutyrate, 2-methylbutyrate, isovalerate, butyrate, valerate, or propionate as a substrate but not with acetate as a substrate. The acetate kinase isozymes were active with acetate and propionate as substrates but not with longer-chain fatty acids as substrates. The acetate kinase isozymes and the branched-chain fatty acid kinase differed in nucleoside triphosphate and cation specificities. Each acetate kinase isozyme had an apparent molecular weight of approximately 125,000, whereas the branched-chain fatty acid kinase had a molecular weight of approximately 76,000. These results show that spirochete MA-2 synthesizes a branched-chain fatty acid kinase specific for leucine, isoleucine, and valine fermentation. It is likely that a phosphate branched-chain amino acids is also synthesized by spirochete MA-2. Thus, in spirochete MA-2, physiological mechanisms have evolved which serve specifically to generate maintenance energy from branched-chain amino acids.


Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 118 ◽  
Author(s):  
Xingyu Zhu ◽  
Shuangfei Li ◽  
Liangxu Liu ◽  
Siting Li ◽  
Yanqing Luo ◽  
...  

Thraustochytriidae sp. have broadly gained attention as a prospective resource for the production of omega-3 fatty acids production in significant quantities. In this study, the whole genome of Thraustochytriidae sp. SZU445, which produces high levels of docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA), was sequenced and subjected to protein annotation. The obtained clean reads (63.55 Mb in total) were assembled into 54 contigs and 25 scaffolds, with maximum and minimum lengths of 400 and 0.0054 Mb, respectively. A total of 3513 genes (24.84%) were identified, which could be classified into six pathways and 44 pathway groups, of which 68 genes (1.93%) were involved in lipid metabolism. In the Gene Ontology database, 22,436 genes were annotated as cellular component (8579 genes, 38.24%), molecular function (5236 genes, 23.34%), and biological process (8621 genes, 38.42%). Four enzymes corresponding to the classic fatty acid synthase (FAS) pathway and three enzymes corresponding to the classic polyketide synthase (PKS) pathway were identified in Thraustochytriidae sp. SZU445. Although PKS pathway-associated dehydratase and isomerase enzymes were not detected in Thraustochytriidae sp. SZU445, a putative DHA- and DPA-specific fatty acid pathway was identified.


Sign in / Sign up

Export Citation Format

Share Document