Aspergillus nidulans contains six possible fatty acyl-CoA synthetases with FaaB being the major synthetase for fatty aci
- PDF / 346,773 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 92 Downloads / 139 Views
ORIGINAL PAPER
Aspergillus nidulans contains six possible fatty acyl-CoA synthetases with FaaB being the major synthetase for fatty acid degradation Kathrin Reiser • Meryl A. Davis • Michael J. Hynes
Received: 30 November 2009 / Revised: 8 February 2010 / Accepted: 10 March 2010 / Published online: 31 March 2010 Springer-Verlag 2010
Abstract Aspergillus nidulans can use a variety of fatty acids as sole carbon and energy sources via its peroxisomal and mitochondrial b-oxidation pathways. Prior to channelling the fatty acids into b-oxidation, they need to be activated to their acyl-CoA derivates. Analysis of the genome sequence identified a number of possible fatty acyl-CoA synthetases (FatA, FatB, FatC, FatD, FaaA and FaaB). FaaB was found to be the major long-chain synthetase for fatty acid degradation. FaaB was shown to localise to the peroxisomes, and the corresponding gene was induced in the presence of short and long chain fatty acids. Deletion of the faaB gene leads to a reduced/abolished growth on a variety of fatty acids. However, at least one additional fatty acyl-CoA synthetase with a preference for short chain fatty acids and a potential mitochondrial candidate (AN4659.3) has been identified via genome analysis. Keywords b-oxidation Fatty acyl-CoA synthetase Aspergillus nidulans Peroxisome
Communicated by Erko Stackebrandt.
Electronic supplementary material The online version of this article (doi:10.1007/s00203-010-0565-9) contains supplementary material, which is available to authorized users. K. Reiser M. A. Davis M. J. Hynes (&) Department of Genetics, University of Melbourne, Parkville, VIC 3010, Australia e-mail: [email protected]
Introduction Filamentous fungi can use a wide range of carbon sources including both short chain fatty acids (SCFAs) and long chain fatty acids (LCFAs). These are degraded by b-oxidation to release acetyl-CoA. Before entering the b-oxidation pathway, FAs need to be activated to their acyl-CoA derivates. This reaction is catalysed by FA-CoA synthetases. These enzymes contain an ATP/AMP signature motif consisting of two highly conserved sequence elements (reviewed in Black et al. 1997; Black and DiRusso 2003; Black and DiRusso 2007). The first one (YTSGTTGXPKGV) lies about 125–130 amino acid residues upstream of the second (GYGXTE). These two sequences have been found in all adenylate forming enzymes. Another highly conserved sequence element typically found in FA-CoA synthetases required for the activation of long chain FAs ([C14) is the FACS signature motif (DGWLHTGDIGXWXPXGXLKIIDRKK), which is believed to be involved in the catalytic function of the protein, most likely in the binding of the substrate. Furthermore, a conserved 35 amino acid sequence, the Mdomain, is found in short chain (SC) and medium chain (MC) length FA-CoA synthetases (Morsczeck et al. 2001). In Echerichia coli, the activation of LCFAs is catalysed by FadD, an inner membrane-associated LCFA-CoA synthetase. When this protein binds ATP, it is thought to be able to retrieve and activa
Data Loading...
