Archaeal chromatin proteins

Zhang, Zhenfeng; Guo, Li; Huang, Li

doi:10.1007/s11427-012-4322-y

Cited by 30 publications

(24 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other upregulated replication and transcription genes included those encoding reverse gyrase, a TFIIB paralog, the M subunit of RNAP, and a putative transcriptional regulator. The gene encoding Sso7d was also upregulated in STIV-infected cells, consistent with the proposed role for the chromatin protein in viral DNA packaging (118). STIV appears to share limited but potentially interesting similarity to SSV2 in eliciting a host response to infection.…”

Section: Figsupporting

confidence: 72%

Archaeal Extrachromosomal Genetic Elements

Wang

Peng

Shah

et al. 2015

Microbiol Mol Biol Rev

Self Cite

View full text Add to dashboard Cite

SUMMARY Research on archaeal extrachromosomal genetic elements (ECEs) has progressed rapidly in the past decade. To date, over 60 archaeal viruses and 60 plasmids have been isolated. These archaeal viruses exhibit an exceptional diversity in morphology, with a wide array of shapes, such as spindles, rods, filaments, spheres, head-tails, bottles, and droplets, and some of these new viruses have been classified into one order, 10 families, and 16 genera. Investigation of model archaeal viruses has yielded important insights into mechanisms underlining various steps in the viral life cycle, including infection, DNA replication and transcription, and virion egression. Many of these mechanisms are unprecedented for any known bacterial or eukaryal viruses. Studies of plasmids isolated from different archaeal hosts have also revealed a striking diversity in gene content and innovation in replication strategies. Highly divergent replication proteins are identified in both viral and plasmid genomes. Genomic studies of archaeal ECEs have revealed a modular sequence structure in which modules of DNA sequence are exchangeable within, as well as among, plasmid families and probably also between viruses and plasmids. In particular, it has been suggested that ECE-host interactions have shaped the coevolution of ECEs and their archaeal hosts. Furthermore, archaeal hosts have developed defense systems, including the innate restriction-modification (R-M) system and the adaptive CRISPR (clustered regularly interspaced short palindromic repeats) system, to restrict invasive plasmids and viruses. Together, these interactions permit a delicate balance between ECEs and their hosts, which is vitally important for maintaining an innovative gene reservoir carried by ECEs. In conclusion, while research on archaeal ECEs has just started to unravel the molecular biology of these genetic entities and their interactions with archaeal hosts, it is expected to accelerate in the next decade.

show abstract

Section: Figsupporting

confidence: 72%

Archaeal Extrachromosomal Genetic Elements

Wang

Peng

Shah

et al. 2015

Microbiol Mol Biol Rev

Self Cite

View full text Add to dashboard Cite

show abstract

“…Sso7d, a member of the Sul7d family, is one of the major chromatin proteins responsible for chromosome organization in Sulfolobus (65). This small basic protein is known to bind dsDNA nonspecifically and induces negative supercoiling (83) as well as compaction of relaxed or positively supercoiled DNA in vitro (64).…”

Section: Discussionmentioning

confidence: 99%

“…3A and B). Sso7d is a small, basic protein, which belongs to the extensively studied Sul7d family of 7-kDa DNA-binding proteins and represents one of the major chromatin proteins of Sulfolobus solfataricus (64,65). Notably, SDS-PAGE analysis of fractions collected from the CsCl gradient showed that Sso7 is exclusively detected in the fraction containing SSV1 virions.…”

Section: Aggregation Of Ssv1 Particles Is Modulated By Ionic and Hydrmentioning

confidence: 99%

Sulfolobus Spindle-Shaped Virus 1 Contains Glycosylated Capsid Proteins, a Cellular Chromatin Protein, and Host-Derived Lipids

Quemin

Pietilä

Oksanen

et al. 2015

J Virol

View full text Add to dashboard Cite

Geothermal and hypersaline environments are rich in virus-like particles, among which spindle-shaped morphotypes dominate. Currently, viruses with spindle-or lemon-shaped virions are exclusive to Archaea and belong to two distinct viral families. The larger of the two families, the Fuselloviridae, comprises tail-less, spindle-shaped viruses, which infect hosts from phylogenetically distant archaeal lineages. Sulfolobus spindle-shaped virus 1 (SSV1) is the best known member of the family and was one of the first hyperthermophilic archaeal viruses to be isolated. SSV1 is an attractive model for understanding virus-host interactions in Archaea; however, the constituents and architecture of SSV1 particles remain only partially characterized. Here, we have conducted an extensive biochemical characterization of highly purified SSV1 virions and identified four virus-encoded structural proteins, VP1 to VP4, as well as one DNA-binding protein of cellular origin. The virion proteins VP1, VP3, and VP4 undergo posttranslational modification by glycosylation, seemingly at multiple sites. VP1 is also proteolytically processed. In addition to the viral DNA-binding protein VP2, we show that viral particles contain the Sulfolobus solfataricus chromatin protein Sso7d. Finally, we provide evidence indicating that SSV1 virions contain glycerol dibiphytanyl glycerol tetraether (GDGT) lipids, resolving a long-standing debate on the presence of lipids within SSV1 virions. A comparison of the contents of lipids isolated from the virus and its host cell suggests that GDGTs are acquired by the virus in a selective manner from the host cytoplasmic membrane, likely during progeny egress. Viruses infecting extremophilic archaea have evolved to withstand very high temperatures, low or high pH, or near-saturating salt concentrations (1-5). Remarkably, most of these viruses do not seem to be evolutionarily related to viruses of bacteria or eukaryotes and display a considerable diversity of unique virion morphotypes (3, 4). Indeed, 11 novel viral families have been established by the International Committee for the Taxonomy of Viruses (ICTV) for the classification of archaeal viruses, emphasizing the uniqueness of rod-shaped, spindle-shaped, dropletshaped, or even bottle-shaped particles that have never been observed among viruses infecting bacteria or eukaryotes (3). Functional studies proved to be highly challenging due to the lack of similarity between the protein sequences and structures of archaeal viruses and those from other viruses and cellular organisms (6-10). Among the morphotypes that are exclusively associated with archaea, spindle-shaped viruses are particularly widespread (11) and have been isolated from highly different environments, including deep-sea hydrothermal vents (12-14), hypersaline environments (15-18), anoxic freshwaters (19), cold Antarctic lakes (20), terrestrial hot springs (21-23), and acidic mines (24).Recently, we refined the evolutionary relationships among spindle-shaped viruses by assessing the morph...

show abstract

“…Thus, it is possible that PolB activity was substantially underestimated at 50 o C. Euryarchaea also appear to differ from crenarchaea in genome packaging. While the former encode archaeal histones, the latter employ unique chromatin proteins, such as Cren7 and Sul7d (Zhang et al, 2012). Despite their differences in sequence and structure, these archaeal chromatin proteins behaved in a similar fashion in modulating strand displacement.…”

Section: Discussionmentioning

confidence: 99%

A euryarchaeal histone modulates strand displacement synthesis by replicative DNA polymerases

Sun

Huang

2016

Sci. China Life Sci.

Self Cite

View full text Add to dashboard Cite

Euryarchaeota and Crenarchaeota, the two main lineages of the domain Archaea, encode different chromatin proteins and differ in the use of replicative DNA polymerases. Crenarchaea possess a single family B DNA polymerase (PolB), which is capable of strand displacement modulated by the chromatin proteins Cren7 and Sul7d. Euryarchaea have two distinct replicative DNA polymerases, PolB and PolD, a family D DNA polymerase. Here we characterized the strand displacement activities of PolB and PolD from the hyperthermophilic euryarchaeon Pyrococcus furiosus and investigated the influence of HPfA1, a homolog of eukaryotic histones from P. furiosus, on these activities. We showed that both PolB and PolD were efficient in strand displacement. HPfA1 inhibited DNA strand displacement by both DNA polymerases but exhibited little effect on the displacement of a RNA strand annealed to single-stranded template DNA. This is consistent with the finding that HPfA1 bound more tightly to double-stranded DNA than to a RNA : DNA hybrid. Our results suggest that, although crenarchaea and euryarchaea differ in chromosomal packaging, they share similar mechanisms in modulating strand displacement by DNA polymerases during lagging strand DNA synthesis.

show abstract

Archaeal chromatin proteins

Cited by 30 publications

References 67 publications

Archaeal Extrachromosomal Genetic Elements

Archaeal Extrachromosomal Genetic Elements

Sulfolobus Spindle-Shaped Virus 1 Contains Glycosylated Capsid Proteins, a Cellular Chromatin Protein, and Host-Derived Lipids

A euryarchaeal histone modulates strand displacement synthesis by replicative DNA polymerases

Contact Info

Product

Resources

About