A GX2GX3G motif facilitates acyl chain sequestration by Saccharomyces cerevisiae acyl carrier protein
| Autor: | Usha Yadav, Garima, Monica Sundd, Rashima Prem |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
CoA
coenzyme A Protein Conformation alpha-Helical Conformational change DSS sodium 4 4-dimethyl-4-silapentanesulfonate SEC size-exclusion chromatography Saccharomyces cerevisiae Proteins ACP acyl carrier protein HSQC heteronuclear single quantum coherence spectroscopy Stereochemistry fatty acid biosynthesis Coenzyme A Saccharomyces cerevisiae Amino Acid Motifs acyl carrier protein Biochemistry Turn (biochemistry) chemistry.chemical_compound ESI-MS electrospray ionization–mass spectrometry chemical shift perturbations type I ACP Threonine NMR nuclear magnetic resonance Molecular Biology Nuclear Magnetic Resonance Biomolecular S. cerevisiae ACP 4′-PP 4′-phosphopantetheine biology Chemistry FAS fatty acid synthesis ScACP Saccharomyces cerevisiae acyl carrier protein type I FAS Cell Biology biology.organism_classification NMR Acyl carrier protein acyl chain sequestration Helix biology.protein acyl-ACP interaction lipids (amino acids peptides and proteins) Heteronuclear single quantum coherence spectroscopy Research Article |
| Zdroj: | The Journal of Biological Chemistry |
| ISSN: | 1083-351X 0021-9258 |
| Popis: | Saccharomyces cerevisiae acyl carrier protein (ScACP) is a component of the large fungal fatty acid synthase I (FAS I) complex. ScACP comprises two subdomains: a conserved ACP domain that shares extensive structural homology with other ACPs, and a unique structural domain. Unlike the metazoan type I ACP that does not sequester the acyl chain, ScACP can partially sequester the growing acyl chain within its hydrophobic core by a mechanism that remains elusive. Our studies on the acyl-ScACP intermediates disclose a unique 188GX2GX3G195 sequence in helix II important for ACP function. Complete loss of sequestration was observed upon mutation of the three glycine in this sequence to valine (G188V/G191V/G195V), while G191V and G188V/G191V double mutants displayed a faster rate of acyl chain hydrolysis. Likewise, mutation of Thr216 to Ala altered the size of the hydrophobic cavity, resulting in loss of C12- chain sequestration. Combining NMR studies with insights from the crystal structure, we show that three glycine's in helix II and a threonine in helix IV favor conformational change, which in turn generate space for acyl chain sequestration. Furthermore, we identified the primary hydrophobic cavity of ScACP, present between the carboxyl end of helix II and IV. The opening of the cavity lies between the second and third turns of helix II and loop II. Overall, the study highlights a novel role of the GX2GX3G motif in regulating acyl chain sequestration, vital for ScACP function. |
| Databáze: | OpenAIRE |
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