Project description:Total RNAs were isolated from the thermophilic archaeon Sulfolobus acidocaldarius MW001 and subjected to Illumina sequencing. A differential gene expression analysis was performed to identify ncRNA in biofilm- associated cells and planktonically grown cells. Additionally, the small RNA subpopulation of the transcriptome was subjected to RNaseR digestion prior to Illumina sequencing. An abundant double-stranded RNA was identified.
Project description:We use MNase-Seq to elucidate primary chromatin architecture in an archaeon without histones, the acido-thermophilic archaeon Thermoplasma acidophilum. Like all members of the Thermoplasmatales, T. acidophilum harbours a HU family protein, HTa, that is highly expressed and protects - like histones but unlike well-characterized bacterial HU proteins – a sizeable fraction of the genome from MNase digestion. Comparing HTa-based chromatin architecture to that of three histone-encoding archaea, Methanothermus fervidus, Haloferax volcanii, and Thermococcus kodakkarensis, we present evidence that HTa is an archaeal histone analog. HTa-protected fragments are GC-rich, display histone-like mono- and dinucleotide patterns around the dyad, exhibit relatively invariant positioning throughout the growth cycle, and show archaeal histone-like oligomerization dynamics. Our results suggest that HTa, a DNA-binding protein of bacterial origin, has converged onto an architectural role filled by histones in other archaea.
