In tonight’s post I will attempt to bridge hydrophobic interactions and life as we know it. It might get philosophical, so bear with me. As many of you probably know, not long ago, Romesberg and colleagues at Scripps created the first organism that can grow and replicate with a completely unnatural base pair in its DNA. The DNA of this organism can, in principle, code for up to 172 amino acids. On a molecular level, the “glue” that holds the novel base pair together is purely hydrophobic in nature (the pair comprises a substituted methylisoquinoline and a methoxynaphthalene). There are no hydrogen bonds there at all:
The most interesting part of this research is how the authors managed to get their cells to replicate. In order to pull this off, they needed to figure out a way to smuggle the new bases inside the E. coli bacteria. The team found a unique protein transporter that was able to specifically take up the aforementioned synthetic bases. As a result, the new base pair was incorporated into DNA and was later found in replicated plasmids.
While there are many hurdles that prevent this system from being truly efficient, there are as many ethical questions that can be posed here. Apparently, the Romesberg study has already resulted in renewed calls to halt research in synthetic biology (for instance, by the ETC group: http://www.etcgroup.org). I am not an expert in these kinds of debates and it is difficult to speculate on the dangers of this science at this point. But I do want to note something else that might be interesting. Without going into a theological discourse, I note that anti-religion zealots such as Richard Dawkins are (ironically) not that far from some of the key principles they try to attack at all costs. I refer to how Dawkins looks back in time to find our ancestors, assuming that evolution is progressive, culminating with us. He does it in his book The Ancestor’s Tale. The amusing feature of this logic is that he ends up with a chain of being that is very similar to what religion promotes, namely that man is the culmination of it all. There is an excellent piece published by Sean Nee in Nature close to 10 years ago (I urge you to read it) that discusses this central issue and presents an alternative view of evolution. This essay offers a conjecture. Nee reminds us that over the past 600 million years a great variety of Bacteria, Archaea and microbial Eukarya have been evolving. And (I quote): “One of the huge species, Homo sapiens, got remarkably self-important. But when, to his surprise, a virus wiped him out, most of life on Earth took no notice at all.”
The lesson here is that we tend to assume too much about our relative significance in the great chain of being. But how does this relate to synthetic biology? We have curious minds. What if we do indeed create a form of life that will prove Nee’s conjecture that we might have gotten somewhat self-important?