title: Single-particle approaches in the analysis of small 2D crystals of the mitochondrial channel VDAC.
abstract: It has been difficult to obtain better than moderate resolution in analysis of electron microscopic images of small, 2D crystals with variable lattice parameters, e.g., crystals of the channel VDAC generated by phospholipase treatment of outer mitochondrial membranes. We demonstrate that applying single-particle analysis methods to correlation-averaged images can lead to significant improvements in the attainable resolution. Application of a soft-edged fitted mask passing only the central unit cell, and excluding the positionally variable adjacent unit cells, allows improved alignment and more sensitive multivariate statistical analysis, needed to guide intelligent merging of data from different crystals.
authors.affiliation: Division of Molecular Medicine, New York State Department of Health, Albany, New York 12201-0509, USA. adri@wadsworth.org
authors.forename: A
authors.initials: A
authors.lastname: Verschoor
authors.forename: W F
authors.initials: WF
authors.lastname: Tivol
authors.forename: C A
authors.initials: CA
authors.lastname: Mannella
mesh_terms: D020285:Cryoelectron Microscopy / Q000379:methods*; D003460:Crystallization; D005656:Fungal Proteins / Q000737:chemistry; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007473:Ion Channels / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry; D008928:Mitochondria / Q000737:chemistry; D008958:Models, Molecular; D009491:Neurospora / Q000648:ultrastructure; D018272:Porins / Q000737:chemistry*; D011487:Protein Conformation; D050994:Voltage-Dependent Anion Channels
chemical_list: D005656:Fungal Proteins; D007473:Ion Channels; D008565:Membrane Proteins; D018272:Porins; D050994:Voltage-Dependent Anion Channels