PMID: 31127102
Zhou BR, Yadav KNS, Borgnia M, Hong J, Cao B, Olins AL, Olins DE, Bai Y, Zhang P
Atomic resolution cryo-EM structure of a native-like CENP-A nucleosome aided by an antibody fragment.
Nat Commun. 2019 May 24;10(1):2301. doi: 10.1038/s41467-019-10247-4.
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 alpha-satellite DNA and solved its structure by the cryo-electron microscopy (cryo-EM) to 2.6 A resolution. In comparison, the corresponding cryo-EM structure of the free CENP-A nucleosome could only reach 3.4 A 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.