In her autobiography in the 2007 Annual Review of Microbiology, Margarita Salas published an electron micrograph of rare beauty. It shows the DNA of phage ø29 casually coiled around itself, with protein TP (for Terminal Protein) at the two ends. Not only is this a fine demonstration of a specific DNA-protein interaction, but the surprisingly symmetrical spiral of the DNA invites speculation about how it coiled itself so elegantly. Any ideas?
Source: Margarita Salas (2007) 40 Years with Bacteriophage ø29.
Annual Review of Microbiology 61: 1-22.
Photo by José M. Sogo
I have a theory as to how it could have coiled up. Assuming that this does not happen in every cell, may be it was the way in which the hydrogen bonds happened to line up. Seeing that it is DNA and all, DNA likes to coil up, thanks to hydrogen bonding. It seems to me that this could very well be the answer. In an addition to my guess, may be the manipulation required in preparing the DNA for EM allowed the hydrogen bonds to line up in just the right way to produce this image. In any case, analyzation aside, it is beautiful and stunningly concentric.
Posted by: Autumn Cochrane | June 30, 2008 at 08:56 PM