Direct structural insight into the substrate-shuttling mechanism of yeast fatty acid synthase by electron cryomicroscopy

• DOI: 10.1073/pnas.0913547107
• Publication Date: 2010-03-16T03:59:34Z
• Authors: Preeti Gipson; Deryck J. Mills; Remco Wouts; Martin Grininger; Janet Vonck; Werner Kühlbrandt
• Keywords: Cryo-Electron Microscopy

Yeast fatty acid synthase (FAS) is a 2.6-MDa barrel-shaped multienzyme complex, which carries out cyclic synthesis of acids. By electron cryomicroscopy single particles we obtained three-dimensional map yeast FAS at 5.9-Å resolution. Compared to the crystal structures fungal FAS, EM reveals major differences and new features that indicate considerably different arrangement complex in solution compared structures, as well high degree variance inside barrel. Distinct density regions reaction chambers next each catalytic domains fitted substrate-binding acyl carrier protein (ACP) domain. In case, this resulted expected distance ∼18 Å from ACP site active domains. The multiple, partially occupied positions within chamber provide direct structural insight into substrate-shuttling mechanism large cellular machine.