Berkeley Lab

Uranium binding complex a potential tool for environmental sequestration of uranium

Purification of uranium binding complex from Pelosinus Strain UFO1. The uranium-binding complex was purified from the membrane fraction by two column chromatography steps A) (anion exchange (DEAE FF) and B) size exclusion (Superose 6)). After the fractionation steps, fractions were analyzed for protein (blue), uranium (red), and phosphorus (green). The flow through fraction from column 1 was used for the second purification step and is denoted by a box. C) The denaturing gel image for purified UBC from fraction 6 of the Superose 6 column (arrow) is shown. The uranium binding complex binds 3.3 U(IV) atoms/ protein complex

Widespread uranium contamination from industrial sources poses hazards to human health and the environment.  ENIGMA researchers from University of Georgia and Lawrence Berkeley National Lab identified a highly abundant uranium-binding complex (UBC) from Pelosinus sp. strain UFO1.  The complex makes up the primary protein component of the S-layer of strain UFO1 and binds 3.3 atoms of U(IV) per heterodimer. While other bacteria have been shown to bind U(VI) on their S-layer, this is the first demonstrated example of U(IV) being bound by an S-layer complex. UBC provides a potential tool for the microbiological sequestration of uranium to clean up contaminated environments

Significance

  • Identified a S-layer complex capable of binding U(IV).
  • Characterized the uranium binding stoichiometry of the uranium binding complex.
  • This uranium binding complex could provide a potential tool for environmental sequestration of uranium.

A Highly Expressed High Molecular Weight S-Layer Complex of Pelosinus Strain UFO1 Binds Uranium. (2017). Thorgersen, M.P., W.A. Lancaster, L. Rajeev, X. Ge, B.J. Vaccaro, F.L. Poole, A.P. Arkin, A. Mukhopadhyay, M.W. Adams. Appl. Environ. Microbiol. 83: (DOI: 10.1128/AEM.03044-16).