OpenEM has a new logo! This O-shaped ring is a protein structure imaged by Mikhail Kudryashev and colleagues at Biozentrum, Universtity of Basel, using cryo-electron microscopy.
The bacterium Vibrio cholerae uses a syringe-like fiber called the type VI secretion system to inject effector molecules into other cells. The outside of this fiber is made up of two proteins, VipA and VipB, which form a helical structure with six spiraling strands. The logo shows the electron density from a short segment of the sheath.
Data for this image is available from three sources:
- micrographs from EMPAIR: EMPIAR-10019
- reconstructed 3D electron density from EMDB: EMD-2699; and a
- molecular model from PDB: 3j9g The logo was created from this data using ChimeraX.
Mikhail Kudryashev, Ray Yu-Ruei Wang, Maximilian Brackmann, Sebastian Scherer, Timm Maier, David Baker, Frank DiMaio, Henning Stahlberg, Edward H. Egelman, and Marek Basler. (2015) Structure of the Type VI Secretion System Contractile Sheath. Cell. 160(5) pp 952-962. Pubmed 25723169 DOI 10.1016/j.cell.2015.01.037
Sidebar image
The colorful background used in the sidebar is also an electron micrograph. This crystallographic orientation map was produced by Dr. Karsten Kunze and Dr. Alla Sologubenko using Transmission Kikuchi Diffraction (TKD). The colors show the orientation of each crystal domain in this nanocrystalline Titanium sample (TEM foil). For more information see the ScopeM page or read more in the Proceedings MC 2013:
K. Kunze, A. Sologubenko, H. Ma, and R. Spolenak. (2013) Orientation contrast imaging and crystallographic orientation mapping using transmission Kikuchi diffraction in the SEM. Proceedings MC 2013. Regensburg, August 25 – 30, 2013. Part 1, pages 744-745. DOI: 10.5283/epub.28734