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Review
. 2022 May 28;15(1):21.
doi: 10.1186/s13072-022-00454-7.

Viral histones: pickpocket's prize or primordial progenitor?

Paul B Talbert  1 , Karim-Jean Armache  2 , Steven Henikoff  3
Affiliations
Review

Viral histones: pickpocket's prize or primordial progenitor?

Paul B Talbert et al. Epigenetics Chromatin. .

Abstract

The common histones H2A, H2B, H3, and H4 are the characteristic components of eukaryotic nucleosomes, which function to wrap DNA and compact the genome as well as to regulate access to DNA for transcription and replication in all eukaryotes. In the past two decades, histones have also been found to be encoded in some DNA viruses, where their functions and properties are largely unknown, though recently histones from two related viruses have been shown to form nucleosome-like structures in vitro. Viral histones can be highly similar to eukaryotic histones in primary sequence, suggesting they have been recently picked up from eukaryotic hosts, or they can be radically divergent in primary sequence and may occur as conjoined histone doublets, triplets, or quadruplets, suggesting ancient origins prior to the divergence of modern eukaryotes. Here, we review what is known of viral histones and discuss their possible origins and functions. We consider how the viral life cycle may affect their properties and histories, and reflect on the possible roles of viruses in the origin of the nucleus of modern eukaryotic cells.

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Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Life cycle of Cotesia and bracovirus. Female Cotesia wasps lay eggs in larvae of moths such as Plutella xylostella and also inject bracovirus virion particles carrying DNA circles that integrate into the chromosomes of the parasitized larvae and favor development of the wasp larvae over the moth larvae. The bracovirus provirus is resident in the wasp genome and transmitted directly to offspring
Fig. 2
Fig. 2
Marseillevirus nucleosome. A Divergent transcription of Hβ–Hα and Hδ–Hγ histone doublet genes. B Cryo-EM structure of Marseillevirus nucleosome made up of a tetramer of two Hβ–Hα and two Hδ–Hγ proteins. The regions linking the separate histone fold domains are marked in red. C Comparison of the Marseillevirus nucleosome and a human nucleosome. Reprinted from Ref. [34], used with permission
Fig. 3
Fig. 3
Viral histone doublets, triplets, and quadruplets. Configurations of predicted histone fold domain proteins in various viruses and metagenomic viral genomes. Green: H4-like; blue: H3-like; red: H2B-like; yellow: H2A-like; orange: no homology to any known protein
Fig. 4
Fig. 4
Maximum Likelihood trees of histone doublets. The trees are unrooted, but drawn as if rooted on archaeal doublets. Archaea (blue); eukaryotes (orange); Marseilleviridae (green); insect iridoviruses (red). Alignments were made with EMBL-EBI Muscle software and manually trimmed to remove the N-terminal tails, leaving the histone fold domains, the αN helix and docking domain of H2A, and the αC helix of H2B. The alignments were used to make maximum likelihood trees with IQ Tree [129] and viewed and annotated with Dendroscope 3.0 [130]. Numbers in parentheses are SH-aLRT support (%)/Ultrafast Bootstrap support (%)
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References

    1. Luger K, Mader AW, Richmond RK, Sargent DF, Richmond TJ. Crystal structure of the nucleosome core particle at 2.8 A resolution. Nature. 1997;389:251–260. doi: 10.1038/38444. - DOI - PubMed
    1. Alva V, Lupas AN. Histones predate the split between bacteria and archaea. Bioinformatics. 2018;35:2349–2353. doi: 10.1093/bioinformatics/bty1000. - DOI - PubMed
    1. Kasinsky HE, Lewis JD, Dacks JB, Ausio J. Origin of H1 linker histones. FASEB J. 2001;15:34–42. doi: 10.1096/fj.00-0237rev. - DOI - PubMed
    1. Dalmasso MC, Sullivan WJ, Jr, Angel SO. Canonical and variant histones of protozoan parasites. Front Biosci (Landmark Ed) 2011;16:2086–2105. doi: 10.2741/3841. - DOI - PubMed
    1. Soo VWC, Warnecke T. Slaying the last unicorn: discovery of histones in the microalga. R Soc Open Sci. 2021;8:202023. doi: 10.1098/rsos.202023. - DOI - PMC - PubMed

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