Atomic resolution cryo-EM structure of a native-like CENP-A nucleosome aided by an antibody fragment.

ABSTRACT: Genomic DNA in eukaryotes is organized into chromatin through association with core histones to form nucleosomes, each distinguished by their DNA sequences and histone variants. Here, we used a single-chain antibody fragment (scFv) derived from the anti-nucleosome antibody mAb PL2-6 to stabilize human CENP-A nucleosome containing a native ?-satellite DNA and solved its structure by the cryo-electron microscopy (cryo-EM) to 2.6?Å resolution. In comparison, the corresponding cryo-EM structure of the free CENP-A nucleosome could only reach 3.4?Å resolution. We find that scFv binds to a conserved acidic patch on the histone H2A-H2B dimer without perturbing the nucleosome structure. Our results provide an atomic resolution cryo-EM structure of a nucleosome and insight into the structure and function of the CENP-A nucleosome. The scFv approach is applicable to the structural determination of other native-like nucleosomes with distinct DNA sequences.

SUBMITTER: Zhou BR 

PROVIDER: S-EPMC6534667 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature