The AFM team of the MEM group, in collaboration with the DNA Damage and Repair team of the VIC group, has made it possible to image for the first time the HU protein of Deinococcus radiodurans by Atomic Force Microscopy. HU is an important, even essential, protein in bacterial nucleotides. A new AFM image processing allows us to observe the positioning of the DrHU protein on native plasmids produced by E. coli as well as on linearized plasmids (image on the left which illustrates the application of the Laplacian-weight filter used in this work). This work highlights two major functions of DrHU in the condensation, but also in the decondensation, of double-stranded DNA. The self-compacting dynamics of naked DNA as well as the concentration of DrHU are important parameters in the cellular function of DrHU.
Image processing and structural interpretations were done by Wendy Chen. AFM imaging was conducted by Jean-Marie Teulon with the participation of Anne-Sophie Banneville on samples prepared by Anne-Sophie.
Chen SWW, Banneville AS, Teulon JM, Timmins J and Pellequer JL (2020) Nanoscale surface structures of DNA bound to Deinococcus radiodurans HU unveiled by atomic force microscopy. Nanoscale 12: 22628-22638