Skip to main content
. Author manuscript; available in PMC: 2023 Mar 3.
Published in final edited form as: Structure. 2021 Nov 26;30(3):371–385.e5. doi: 10.1016/j.str.2021.11.002

Figure 2. Equimolar stoichiometry and conformations of Lig-PCNA-DNA by negative stain-EM.

Figure 2.

(A, B) A complex of Lig and PCNA with ligatable DNA was measured to be ~170 kDa by SEC-MALS (A) and contained equimolar protein (SDS-PAGE) and DNA (agarose) (B). (C–E) Lig and PCNA were mixed with ligatable DNA and used for NS-EM, resulting in three conformers (“OBD-front”, “OBD-up”, “OBD-out”) each showing two contacts between the upper (Lig) and lower (PCNA) portions of the 3D reconstructions, but differing in the distal extremity representing the OBD. (F, G) The crystallized Lig DBD and AdD domains match the upper density (F) and the crystal structure of PCNA fits the toroidal density (G). (H) A control complex of PCNA with DNA resulted in a NS-EM reconstruction of two PCNA rings on DNA. See also Figure S2.