6IS8

Crystal structure of ZmMoc1 D115N mutant in complex with Holliday junction

Summary for 6IS8

• Entry DOI: 10.2210/pdb6is8/pdb
• Descriptor: Monokaryotic chloroplast 1, DNA (33-MER), MAGNESIUM ION, ... (6 entities in total)
• Functional Keywords: holliday junction resolvase-dna complex, dna binding protein-dna complex, dna binding protein/dna
• Biological source: Zea mays (Maize); More
• Total number of polymer chains: 4
• Total formula weight: 58221.91

Authors

Lin, Z.,Lin, H.,Zhang, D.,Yuan, C. (deposition date: 2018-11-15, release date: 2019-10-23, Last modification date: 2023-11-22)

Primary citation

Lin, H.,Zhang, D.,Zuo, K.,Yuan, C.,Li, J.,Huang, M.,Lin, Z.
Structural basis of sequence-specific Holliday junction cleavage by MOC1.
Nat.Chem.Biol., 15:1241-1248, 2019

PubMed Abstract: The Holliday junction (HJ) is a key intermediate during homologous recombination and DNA double-strand break repair. Timely HJ resolution by resolvases is critical for maintaining genome stability. The mechanisms underlying sequence-specific substrate recognition and cleavage by resolvases remain elusive. The monokaryotic chloroplast 1 protein (MOC1) specifically cleaves four-way DNA junctions in a sequence-specific manner. Here, we report the crystal structures of MOC1 from Zea mays, alone or bound to HJ DNA. MOC1 uses a unique β-hairpin to embrace the DNA junction. A base-recognition motif specifically interacts with the junction center, inducing base flipping and pseudobase-pair formation at the strand-exchanging points. Structures of MOC1 bound to HJ and different metal ions support a two-metal ion catalysis mechanism. Further molecular dynamics simulations and biochemical analyses reveal a communication between specific substrate recognition and metal ion-dependent catalysis. Our study thus provides a mechanism for how a resolvase turns substrate specificity into catalytic efficiency.

PubMed: 31611704
DOI: 10.1038/s41589-019-0377-4

Experimental method

X-RAY DIFFRACTION (1.68 Å)