Korarchaeum cryptofilum

Introduction

Candidatus Korarchaeum cryptofilum is a species of the proposed phylum Korarchaeota, or Xenarchaeota of the Archaea. The phylum is notoriously difficult to study given the environment in which it lives. The Archean phylum is found mainly in hydrothermal environments such as hot springs, shallow water, and deep ocean. The organism's genome has mainly been studied to open understanding of Archaean evolution due to its distant detachment on the Archaea phyla.

Ca. K. cryptofilum. Notice rod shape of the Archaea. https://sites.google.com/site/chskorarchaeota1

Discovery

The phylum Korarchaeota was only recently discovered in 1996 by a team studying Archaea in hot springs located in Yellowstone National Park. By sequencing the ribosomal RNA of many uncultivated archaeans found in a hot spring, two outlying sequences were found. The two outlying sequences were used as evidence for the proposal of a new phylum "Korarchaeota"

Genetics and Structure

Korarchaeum cryptofilum is an ultrathin filamentous heterotroph, mostly living through anaerobic metabolism of peptide fermentation and protein broken down into H₂. The organism uses enzymes such as peptidase, transaminases, and ATPase. The genome of Ca. K. cryptofilum is a circular chromosome 1,590,757 base pairs long with an average G+C content of 49%. AUG is the start codon for 72.4% of the genome for understood protein-coidng genes, with UUG and GUG at 17.6% and 10% respectively. The arCOG of the archaean phyla crenarchaeota and euryarchaeota when compared with the sequenced genome of Ca. K. cryptofilum, showed that the organism shares its replication, recombination, repair, and cell division genes with that of crenarchaeota while it shares most of its transcription and translation genes with euryarcahaeota. The unusual similarity to Crenarchaeota and Euryarchaeota in the archaeons genome suggest its genome has "retained features that represent an ancestral archaeal form, existing before the occurence of the evolutionary bifurcation into Crenarchaeota and Euryarchaeota".

Chromosome replication is provoked by two orc1/cdc6 homologous and one minichromosome maintenance protein complex. There are multiple DNA-dependent DNA polymerases. For transcription, Ca. K. cryptofilum has typical archaeal DNA-dependent RNA polymerase subunits. The Archaeon has three rRNA genes (16S, 23S, and 5S rRNA). The organism has shown to produce 33 23S r-proteins and 27 16S r-proteins on its rRNA operon. The species is also found to have 45 tRNA genes on its genome with one initiator and 45 elongator tRNAs.
The size of Candidatus Korarchaeum cryptofilum is 0.16-0.18μm in diameter with a varying length. .

Microbiome

The Microbiome of Candidatus Korarchaeum cryptofilum is extreme compared to humans. The archaeon is found in obsidian pools at the Yellowstone National Park in

Include some current research, with a second image.

The population of the Korachaeota is generally minute in its microbiome living in the biome. However in some cases they constitute 7% of all Archaea.

Conclusion

Candidatus Korarchaeum cryptofilum is a relative unknown Archaeon microorganism of the minor phylum Korarchaeota. Little research has been performed on it but key insights on Archaean evolution has been discovered, causing Candidatus Korarchaeum cryptofilum to be used as a reference species.

References

Edited by [Charlie Stutz], student of Joan Slonczewski for BIOL 116 Information in Living Systems, 2019,