Hey community,
I’m currently processing a dataset of a protein that seems to assemble into a dimer in solution.
However, for the first time, I found out a weird set of particles, sorted with 2D classification.
I’m hereby asking if some of you may help me to discover what it could be.
It’s a star-shaped object, about 90 Å diameter. Buffer used is 100 mM KPI.
Here are 2D classes along with the result of an ab-initio model with 26k particles.
Thanks in advance
Kevin
Expression system?
Looks very much like a AAA+ ATPase - something like p97 (e.g compare 2D classes here: https://www.biorxiv.org/content/10.1101/2021.08.10.455711v1.full) - but 90Å is a bit smaller than I’d expect. We have seen p97 as a contaminant before in eukaryotic tissue extracts
The 2nd class in your figure looks like GTP cyclohydrolase (GCH) decamer.
I happened to get a high resolution structure of GCH and identified it. The samples are purified from E. coli expression system.
