Summary information and primary citation

PDB-id
6om3; SNAP-derived features in text and JSON formats; DNAproDB
Class
structural protein-DNA
Method
X-ray (3.3 Å)
Summary
Crystal structure of the orc1 bah domain in complex with a nucleosome core particle
Reference
De Ioannes P, Leon VA, Kuang Z, Wang M, Boeke JD, Hochwagen A, Armache KJ (2019): "Structure and function of the Orc1 BAH-nucleosome complex." Nat Commun, 10, 2894. doi: 10.1038/s41467-019-10609-y.
Abstract
The Origin Recognition Complex (ORC) is essential for replication, heterochromatin formation, telomere maintenance and genome stability in eukaryotes. Here we present the structure of the yeast Orc1 BAH domain bound to the nucleosome core particle. Our data reveal that Orc1, unlike its close homolog Sir3 involved in gene silencing, does not appear to discriminate between acetylated and non-acetylated lysine 16, modification states of the histone H4 tail that specify open and closed chromatin respectively. We elucidate the mechanism for this unique feature of Orc1 and hypothesize that its ability to interact with nucleosomes regardless of K16 modification state enables it to perform critical functions in both hetero- and euchromatin. We also show that direct interactions with nucleosomes are essential for Orc1 to maintain the integrity of rDNA borders during meiosis, a process distinct and independent from its known roles in silencing and replication.

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