7DPD

Human MCM9 N-terminal domain

Summary for 7DPD

• Entry DOI: 10.2210/pdb7dpd/pdb
• Descriptor: DNA helicase MCM9, ZINC ION, SODIUM ION, ... (4 entities in total)
• Functional Keywords: zinc finger, dna binding, dna binding protein
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 2
• Total formula weight: 66300.97

Authors

Li, J.,Liu, L.,Liu, Y. (deposition date: 2020-12-18, release date: 2021-05-19, Last modification date: 2024-04-03)

Primary citation

Li, J.,Yu, D.,Liu, L.,Liang, H.,Ouyang, Q.,Liu, Y.
Structural study of the N-terminal domain of human MCM8/9 complex.
Structure, 29:1171-1181.e4, 2021

PubMed Abstract: MCM8/9 is a complex involved in homologous recombination (HR) repair pathway. MCM8/9 dysfunction can cause genome instability and result in primary ovarian insufficiency (POI). However, the mechanism underlying these effects is largely unknown. Here, we report crystal structures of the N-terminal domains (NTDs) of MCM8 and MCM9, and build a ring-shaped NTD structure based on a 6.6 Å resolution cryoelectron microscopy map. This shows that the MCM8/9 complex forms a 3:3 heterohexamer in an alternating pattern. A positively charged DNA binding channel and a putative ssDNA exit pathway for fork DNA unwinding are revealed. Based on the atomic model, the potential effects of the clinical POI mutants are interpreted. Surprisingly, the zinc-finger motifs are found to be capable of binding an iron atom as well. Overall, our results provide a model for the formation of the MCM8/9 complex and provide a path for further studies.

PubMed: 34043945
DOI: 10.1016/j.str.2021.05.006

Experimental method

X-RAY DIFFRACTION (2.55 Å)