Mimivirus

While reading, Keat's Telescope, I read an interesting entry on Mimivirus.

I've been reading a bit on this weird creature. Last year its genome was sequenced (see the Science article). It is 1.2Mbp (longer than some eubacteria) and has over 10,000 genes, some of which are house keeping genes such as tRNAs and amino-acyl transfer RNA synthetases (proteins that load up the tRNAs with amino acids). Infact it was originally thought to be a bacteria, you can see it by light microscopy ... then someone looked at it in an EM (electron microscope) and saw it's true nature. In comparing it's house keeping genes to homologues in bacteria and eukaryotes, it's thought that Mimvirus is so ancient that it may represent a fourth branch in the tree of life (along with eubacteria, archaebacteria and eukaryotes).

To read more, check out the March edition of Discover Magazine.

Refs:
Bernard La Scola et al., A Giant Virus in Amoebae. Science (2003) 299:2033
Raoult et al., The 1.2-Mb Genome Sequence of Mimivirus. Science (2004) 306:1344 - 1350