A C-terminus region (a.a. 318-393) of p53 directly binds MDC1-tBRCT.

<p>(a) His-tBRCT retrieves p53 fragments consisting a.a. 318-393: Bacterially expressed His-tBRCT was incubated with different radio-labeled fragments of p53-HA expressed in reticulocytes (for details see schematic representations below). Following His pull-down reactions the labeled p53 fragments (in the input or those retrieved by His-tBRCT) were visualized by autoradiography. (b) p53 fragments containing a.a 318-393 bind tBRCT-MDC1: Fragments of p53 fused to GST (for details see schematic representations below) were expressed in bacteria and purified. Following incubation with radio-labeled His-tBRCT and GST pull-down reactions, His-tBRCT visualized by using autoradiography. Input is 5% of His-tBRCT added to the reaction. The same gels were used for autoradiography and Coomassie blue staining in B. (c) GST pull-down using a.a. 318-393 of p53 fused to GST (GST-p53Cter) for His-FHA or His-tBRCT, followed by Coomassie blue staining.