arsenic???

OK, this is crazy. Apparently, researchers at NASA have found a new bacteria, GFAJ-1, which engineers all of the components required for life -- DNA, RNA, proteins, sugars -- with arsenic instead of phosphorus, making it a new form of life entirely different from anything else we've ever seen. They apparently isolated it from some poisonous lake in California??

Here are two links. I need to read more about this. Basically, the inherent idea that all life requires six basic elements: carbon, oxygen, hydrogen, nitrogen, phosphorus, and sulfur -- is wrong. Not requiring phosphorous might not seem like a big deal - until you realize that it is:

• the linkage unit between every base pair of DNA or RNA
• the critical on/off switch for every signal transduction pathway that drives pretty all metabolic activity in cells
• oh, right, the fundamental basis of cellular energetics (ATP)

Now, arsenic is from the same family of elements as phosphorus, lying just below it on the periodic table. In fact, its substitution for phosphorus is largely responsible for its toxicity (as shown by its competitive inhibition by exogenous phosphorus added to fungal cultures).

Crazy.