Structural Studies of Fatty Acyl-(Acyl Carrier Protein) Thioesters Reveal a Hydrophobic Binding Cavity that Can Expand to Fit Longer Substrates.Roujeinikova, A., Simon, W.J., Gilroy, J., Rice, D.W., Rafferty, J.B., Slabas, A.R.
(2007) J.Mol.Biol. 365: 135-145
- PubMed: 17059829
- DOI: 10.1016/j.jmb.2006.09.049
- Primary Citation of Related Structures:  2FAC, 2FAD
- PubMed Abstract:
A knowledge of the structures of acyl chain loaded species of the acyl carrier protein (ACP) as used in fatty acid biosynthesis and a range of other metabolic events, is essential for a full understanding of the molecular recognition at the heart of ...
A knowledge of the structures of acyl chain loaded species of the acyl carrier protein (ACP) as used in fatty acid biosynthesis and a range of other metabolic events, is essential for a full understanding of the molecular recognition at the heart of these processes. To date the only crystal structure of an acylated species of ACP is that of a butyryl derivative of Escherichia coli ACP. We have now determined the structures of a family of acylated E. coli ACPs of varying acyl chain length. The acyl moiety is attached via a thioester bond to a phosphopantetheine linker that is in turn bound to a serine residue in ACP. The growing acyl chain can be accommodated within a central cavity in the ACP for transport during the elongation stages of lipid synthesis through changes in the conformation of a four alpha-helix bundle. The results not only clarify the means by which a substrate of varying size and complexity is transported in the cell but also suggest a mechanism by which interacting enzymes can recognize the loaded ACP through recognition of surface features including the conformation of the phosphopantetheine linker.
Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield S10 2TN, UK.