The DNA-binding protein HTa from Thermoplasma acidophilum is an archaeal histone analog
- MRC London Institute of Medical Sciences (LMS), United Kingdom
Abstract
Histones are a principal constituent of chromatin in eukaryotes and fundamental to our understanding of eukaryotic gene regulation. In archaea, histones are widespread but not universal: several lineages have lost histone genes. What prompted or facilitated these losses and how archaea without histones organize their chromatin remains largely unknown. Here, we elucidate primary chromatin architecture in an archaeon without histones, Thermoplasma acidophilum, which harbours a HU family protein (HTa) that protects part of the genome from micrococcal nuclease digestion. Charting HTa-based chromatin architecture in vitro, in vivo and in an HTa-expressing E. coli strain, we present evidence that HTa is an archaeal histone analog. HTa preferentially binds to GC-rich sequences, exhibits invariant positioning throughout the growth cycle, and shows archaeal histone-like oligomerization behaviour. Our results suggest that HTa, a DNA-binding protein of bacterial origin, has converged onto an architectural role filled by histones in other archaea.
Data availability
All sequencing data generated for this study have been deposited in GEO under accession code GSE127728.
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The DNA-binding protein HTa from Thermoplasma acidophilum is an archaeal histone analogNCBI Gene Expression Omnibus, GSE127728.
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Thermococcus kodakarensis MNase-SeqNCBI Sequence Read Archive, SRR495445.
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Haloferax volcanii nucleosome mapNCBI Sequence Read Archive, SRR574592.
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The role of archaeal histones in gene expression - a synthetic biology perspectiveNCBI Gene Expression Omnibus, GSE127678.
Article and author information
Author details
Funding
Medical Research Council (MC_A658_5TY40)
- Tobias Warnecke
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Joseph Thomas Wade, Wadsworth Center, New York State Department of Health, United States
Version history
- Received: October 7, 2019
- Accepted: November 10, 2019
- Accepted Manuscript published: November 11, 2019 (version 1)
- Version of Record published: November 25, 2019 (version 2)
Copyright
© 2019, Hocher et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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The DNA-binding protein HTa from Thermoplasma acidophilum is an archaeal histone analog
eLife 8:e52542.
https://doi.org/10.7554/eLife.52542
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