A short time ago, a study describing the discovery of a bacterium that could apparently utilize arsenate in place of phosphate was published in Science. This report has since generated a lot of discussion and debate in the blog-o-sphere, most of it rather uncomplementary. I count myself among those who are skeptical of the more daring of the authors’ claims.
Something I found curious was the gel in Fig. 2A, an analysis of nucleic acids isolated from bacteria grown in arsenate-rich (middle lane) or phosphate-rich (right lane) media: Read the rest of this entry »
… thanks to my kids and their thoughtfulness this Christmas.
One of those Daddy’s stories things. I forget the details, but it had something to do with the history of computation – before the iPhone calculator was the TI83 and trusty HP calculators, preceded by the ca. $200 four-function calculators, preceded by the slide rule, preceded by the abacus, etc., etc. (Lots of gaps to fill in, I’m sure. But that’s not the point.) Well, the concept of the slide rule caught someone’s fancy, which led to this gift.
So bring on the ice storms. I’m prepared.
A recent article in RNA – “The exozyme model: A continuum of functionally distinct complexes” – provides at once a timely review of exosome structure and function, and an interesting hypothesis that attempts to explain some interesting features of the exosome as it is found in different eukaryotes.
Recall that the exosome is the term for a (THE) RNA degrading machine in eukaryotes, and that it is analogous in many ways to the degradosome in bacteria. Over the years, various and sundry exosome subunits have been implicated by genetics or biochemistry in numerous RNA processing and degrading events or systems. However, there are differences, in terms of subunit composition and activity, between different organisms. Because of these differences (that I won’t list here – Kiss and Andrulis do an excellent job that would take thousands of words to summarize), the authors of the cited review propose that the “exosome” is better thought of as a collection of “exozymes”, all of which share some subset of the subunits that collectively are usually associated with the conceptual exosome. In the authors’ own words: Read the rest of this entry »