Parallel origins of the nucleosome core and eukaryotic transcription from Archaea
Computational sequence analysis of 10 available archaean histone-like proteins has shown that this family is not only divergently related to the eukaryotic core histones H2A/B, H3, and H4, but also to the central domain of subunits A and C of the CCAAT-binding factor (CBF), a transcription factor associated with eukaryotic promoters. Despite the low sequence identity, it is unambiguously shown that the core histone fold shares a common evolutionary history. Archaean histones and the two CBF families show a remarkable variability in contrast to eukaryotic core histones. Conserved residues shared between families are identified, possibly being responsible for the functional versatility of the core histone fold. The H4 subfamily is most similar to archaean proteins and may be the progenitor of the other core histones in eukaryotes. While it is not clear whether archaean histones are more actively involved in transcription regulation, the present observations link two processes, nucleosomal packing and transcription in a unique way. Both these processes, evidently hybrid in Archaea, have originated before the ermergence of the eukaryotic cell.
Periodic binding of individual core histones to DNA: inadvertent purification of the core histone H2B as a putative enhancer-binding factor
The nucleosomal core histone octamer at 3.1 A resolution: a tripartite protein assembly and a left-handed superhelix
The B subunit of a rat heteromeric CCAAT-binding transcription factor shows a striking sequence identity with the yeast Hap2 transcription factor
HMf, a DNA-binding protein isolated from the hyperthermophilic archaeon Methanothermus fervidus, is most closely related to histones
Recombinant rat CBF-C, the third subunit of CBF/NFY, allows formation of a protein-DNA complex with CBF-A and CBF-B and with yeast HAP2 and HAP3
Histone-encoding genes from Pyrococcus: evidence for members of the HMf family of archaeal histones in a non-methanogenic Archaeon
CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice
Topography of the histone octamer surface: repeating structural motifs utilized in the docking of nucleosomal DNA
The KH domain occurs in a diverse set of RNA-binding proteins that include the antiterminator NusA and is probably involved in binding to nucleic acid
Two histone fold proteins, CHRAC-14 and CHRAC-16, are developmentally regulated subunits of chromatin accessibility complex (CHRAC)
A minimal estimate for the gene content of the last universal common ancestor--exobiology from a terrestrial perspective
Archaeal RNA Polymerase
Archaeal RNA polymerases are most similar to eukaryotic RNA polymerase II but require the support of only two archaeal general transcription factors, TBP (TATA-box binding protein) and TFB (archaeal homologue of the eukaryotic general transcription factor TFIIB) to initiate basal transcription. Here is the latest research on archaeal RNA polymerases.