Development of Copper Storage Protein Csp1 as an Electron-Dense “Bio Tag” for Facilitating Structural Determination of Small (< 100 kDa) Proteins by single-particle Cryo EM Methods.
EMSL Project ID
51283
Abstract
Small (< 100 kDa) proteins are challenging to study by standard single-particle cryo-EM techniques, due to their very low signal to noise ratios in images. Heavy atoms could potentially overcome this problem, as they scatter electrons differently than traditional atoms in proteins, and thus yield enhanced contrast in images. To exploit this concept, we are developing the use of a small metal binding protein, called Csp1, as an electron-rich “bio-tag” in such studies. A tetramer of Csp1 weighs only 54 kDa, yet can bind up to 52 metal ions. Moreover, Csp1 can bind different metals (copper, silver, gold), providing a potential range of contrast enhancements. Our goal is to: i) determine if Csp1 facilitates cryo-EM structural studies; ii) quantify contrast improvements obtained when using different metals; iii) establish alternate ways to combine Csp1 with small proteins; and iv) further optimize the use of Csp1 through protein engineering.
Project Details
Start Date
2020-02-15
End Date
2021-03-17
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members