Molecular cloning of the yeast fatty acid synthetase genes, FAS1 and FAS2: Illustrating the structure of the FAS1 cluster gene by transcript mapping and transformation studies

Schweizer, Michael; Lebert, Cordula; Höltke, Joachim; Roberts, Lilian M.; Schweizer, Eckhart

doi:10.1007/bf00425558

Cited by 40 publications

(25 citation statements)

References 40 publications

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“…Subsequently, acetyl-Sp and malonyl-Sc thioesters condense to enzyme-bound acetoacetate, thereby initiating the elongation cycle. Isolation and sequencing of the two S. cerevisiae FAS genes, FAS1 and FAS2, subsequently confirmed the chemical structure and location of the two thiol and two hydroxyl acylation sites in yeast FAS (23,67,94,138,141,142). SHp was identified as Cys1305 in the KS domain of FAS2.…”

Section: Fas Catalytic Centersmentioning

confidence: 78%

Microbial Type I Fatty Acid Synthases (FAS): Major Players in a Network of Cellular FAS Systems

Schweizer

Hofmann

2004

Microbiol Mol Biol Rev

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321

286

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The present review focuses on microbial type I fatty acid synthases (FASs), demonstrating their structural and functional diversity. Depending on their origin and biochemical function, multifunctional type I FAS proteins form dimers or hexamers with characteristic organization of their catalytic domains. A single polypeptide may contain one or more sets of the eight FAS component functions. Alternatively, these functions may split up into two different and mutually complementing subunits. Targeted inactivation of the individual yeast FAS acylation sites allowed us to define their roles during the overall catalytic process. In particular, their pronounced negative cooperativity is presumed to coordinate the FAS initiation and chain elongation reactions. Expression of the unlinked genes, FAS1 and FAS2, is in part constitutive and in part subject to repression by the phospholipid precursors inositol and choline. The interplay of the involved regulatory proteins, Rap1, Reb1, Abf1, Ino2/Ino4, Opi1, Sin3 and TFIIB, has been elucidated in considerable detail. Balanced levels of subunits α and β are ensured by an autoregulatory effect of FAS1 on FAS2 expression and by posttranslational degradation of excess FAS subunits. The functional specificity of type I FAS multienzymes usually requires the presence of multiple FAS systems within the same cell. De novo synthesis of long-chain fatty acids, mitochondrial fatty acid synthesis, acylation of certain secondary metabolites and coenzymes, fatty acid elongation, and the vast diversity of mycobacterial lipids each result from specific FAS activities. The microcompartmentalization of FAS activities in type I multienzymes may thus allow for both the controlled and concerted action of multiple FAS systems within the same cell

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Section: Fas Catalytic Centersmentioning

confidence: 78%

Microbial Type I Fatty Acid Synthases (FAS): Major Players in a Network of Cellular FAS Systems

Schweizer

Hofmann

2004

Microbiol Mol Biol Rev

Self Cite

321

286

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“…The mechanism of resistance specified by AFG2 is unknown, but it appears to be different from that of gene YAP1 and the known genetic mechanisms leading to multiple or pleiotropic drug resistance in yeast. As expected, we did not isolate the yeast enoyl-(acyl carrier protein) reductase, because this enzymatic activity is part of the multifunctional fatty acid synthase and therefore structurally very different from that in E. coli (35).…”

Section: Discussionmentioning

confidence: 98%

Diazaborine Resistance in the Yeast Saccharomyces cerevisiae Reveals a Link between YAP1 and the Pleiotropic Drug Resistance Genes PDR1 andPDR3

Wendler

Bergler

Prutej

et al. 1997

Journal of Biological Chemistry

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We have investigated the mechanisms underlying resistance to the drug diazaborine in Saccharomyces cerevisiae. We used UV mutagenesis to generate resistant mutants, which were divided into three different complementation groups. The resistant phenotype in these groups was found to be caused by allelic forms of the genes AFG2, PDR1, and PDR3. The AFG2 gene encodes an AAA (ATPases associated to a variety of cellular activities) protein of unknown function, while PDR1 and PDR3 encode two transcriptional regulatory proteins involved in pleiotropic drug resistance development. The isolated PDR1-12 and PDR3-33 alleles carry mutations that lead to a L1044Q and a Y276H exchange, respectively. In addition, we report that overexpression of Yap1p, the yeast homologue of the transcription factor AP1, results in a diazaborine-resistant phenotype. The YAP1-mediated diazaborine resistance is dependent on the presence of functional PDR1 and PDR3 genes, although PDR3 had a more pronounced effect. These results provide the first evidence for a functional link between the Yap1p-dependent stress response pathway and Pdr1p/Pdr3p-dependent development of pleiotropic drug resistance.

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“…In contrast to the aforementioned catalytic sites, the ketoreductase, enoyl reductase, and dehydratase domains cannot be labelled by substrate binding. Instead, they have been localized by deletion mapping of appropriate yeast FAS mutations (23). Because of the colinearity of their overall sequences, the respective domains in the B. ammoniagenes fasA and fasB genes have been attributed to positions corresponding to those of the yeast enzyme.…”

Section: Discussionmentioning

confidence: 99%

Identification and functional differentiation of two type I fatty acid synthases in Brevibacterium ammoniagenes

et al. 1996

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The fatty acid synthase (FAS) from Brevibacterium ammoniagenes is a homohexameric multienzyme complex that catalyzes the synthesis of both saturated and unsaturated fatty acids. By immunological screening of a B. ammoniagenes expression library, an fas DNA fragment was isolated and subsequently used to clone the entire gene together with its flanking sequences. Within 10,525 bp of sequenced DNA, the 9,189-bp FAS coding region was identified, corresponding to a protein of 3,063 amino acids with a molecular mass of 324,910 Da. This gene (fasA) encodes, at its 5 end, the same amino acid sequence as is observed with purified B. ammoniagenes FAS. A second reading frame encoding another B. ammoniagenes FAS variant (FasB) had been identified previously. Both sequences are colinear and exhibit 61 and 47% identity at the DNA and protein levels, respectively. By using specific antibodies raised against a unique peptide sequence of FasB, this enzyme was shown to represent only 5 to 10% of the cellular FAS protein. Unlike the majority of procaryotes, the coryneform bacterium Brevibacterium ammoniagenes contains an aggregated type I fatty acid synthase (FAS) multienzyme complex (5, 6). Apart from B. ammoniagenes, FAS proteins with this structural organization have also been found within the genera Mycobacterium (7, 26) and Corynebacterium (1). The taxonomic relatedness of B. ammoniagenes to corynebacteria in particular had already been proposed earlier, mainly on the basis of the occurrence of mycolic acid as a common constituent of their cell walls (24). In type I FASs, at least eight functionally different catalytic domains are integrated into either a single (bacteria, animals) or two different (fungi) multifunctional proteins (13). According to the pioneering work of Kawaguchi and coworkers (17), the B. ammoniagenes FAS complex is an ␣ 6 homomultimer with a molecular mass of about 2.0 MDa. In contrast to the eucaryotic FAS enzymes, but like the dissociated type II bacterial FAS systems (3, 14), the B. ammoniagenes type I FAS contains a 3-hydroxydecanoyl-␤,␥-dehydratase as an additional component; thus, both saturated and unsaturated fatty acids are synthesized by this enzyme (5). In a first attempt to investigate the molecular structure of this exceptional multifunctional FAS protein in more detail, we recently isolated and sequenced a 9,312-bp fas-like reading frame from B. ammoniagenes (16). The gene product encoded by this DNA exhibited 46% sequence similarity to yeast FAS, and its order of catalytic domains was colinear to a hypothetical head-to-tail fusion of the two yeast FAS subunits (16). However, disruption of this fas-like reading frame produced no FAS-defective B. ammoniagenes mutants, indicating that either it is not an FAS coding gene of B. ammoniagenes at all or it is not the only one. As will be reported in this paper, a continued immunological search indeed resulted in the isolation of a second B. ammoniagenes fas gene. Unlike the previously isolated fas-like DNA, the coding region for the N-terminal amin...

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Molecular cloning of the yeast fatty acid synthetase genes, FAS1 and FAS2: Illustrating the structure of the FAS1 cluster gene by transcript mapping and transformation studies

Cited by 40 publications

References 40 publications

Microbial Type I Fatty Acid Synthases (FAS): Major Players in a Network of Cellular FAS Systems

Microbial Type I Fatty Acid Synthases (FAS): Major Players in a Network of Cellular FAS Systems

Diazaborine Resistance in the Yeast Saccharomyces cerevisiae Reveals a Link between YAP1 and the Pleiotropic Drug Resistance Genes PDR1 andPDR3

Identification and functional differentiation of two type I fatty acid synthases in Brevibacterium ammoniagenes

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