IngentaConnect Selenoproteins and the Metabolic Features of the Archaeal Ancesto...

Author: Foster, Charles B.

Source: Molecular Biology and Evolution, Volume 22, Number 3, March 2005 , pp. 383-386(4)

Abstract:

In all three branches of life, some organisms incorporate the rare amino acid selenocysteine. Selenoproteins are relevant to the controversy over the metabolic features of the archaeal ancestor of eukaryotes because among archaea, several known selenoproteins are involved in methanogenesis and autotrophic growth. Although the eukaryotic selenocysteine-specific translation apparatus and at least one selenoprotein appear to be of archaeal origin, selenoproteins have not been identified among sulfur-metabolizing crenarchaeotes. In this regard, both the phylogeny and function of archaeal selenoproteins are consistent with the argument that the archaeal ancestor was a methanogen. Selenium, however, is abundant in sulfur-rich environments, and some anaerobic bacteria reduce sulfur and have selenoproteins similar to those in archaea. As additional archaeal sequence data becomes available, it will be important to determine whether selenoproteins are present in nonmethanogenic archaea, especially the sulfur-metabolizing crenarchaeotes.

Keywords: archaea; origin of life; methanogen; sulfur; hydrogen hypothesis; crenarchaeote

Document Type: Research article

DOI: 10.1093/molbev/msi007

The full text electronic article is available for purchase. You will be able to download the full text electronic article after payment.

$40.19 plus tax Refund Policy

Selenoproteins and the Metabolic Features of the Archaeal Ancestor of Eukaryotes