Fig. 2: Distinct segments of Dbf4 mediate the docking of DDK onto the DH.
From: Structural Insight into the MCM double hexamer activation by Dbf4-Cdc7 kinase
a Side view of the DH-DDK structure with MCM subunits shown in surface presentation and DDK in cartoon presentation. For clarity of Dbf4 segments, Cdc7 is displayed in transparency. The NTD-As of Mcm2, Mcm6, and Mcm4, Dbf4, and Cdc7 are color-coded and labeled. b Schematic domain organization of Dbf4. Dashed lines denote highly disordered segments which are not resolved in the DH-DDK structure. c Dbf4 motif N binds to the NTD-A of Mcm2 using its BRCT domain. The NTE (residues 1-180) of Mcm2 is highly flexible in this structure. The resolved N- and C-terminal residues are labeled as indicated. d Dbf4-M6NB motif is docked onto the NTD-A of Mcm6. e, f The NTD-A of Mcm4 interacts with the M4NB and motif C of Dbf4. The ZF of Mcm7 and the very N-terminal loop of Mcm5’ also show weak interaction with the M4NB motif. Two distinct binding surfaces on Mcm4-NTD-A can be found for Dbf4 motif C from States I (e) and II (f) of the DH-DDK structure. g–j Magnified views of the boxed regions in (c–e), highlighting the interaction details of Dbf4 with the NTD-As. Side chains of selected residues at the interfaces are shown in stick model.
