The story of how I became interested in Photosystem II and photosynthesis

Photosystem II, the water oxidizing enzyme of photosynthesis, has been the main subject of my research since I was an undergraduate student. I have studied it using many different approaches from biochemical to evolutionary.

We have to go back to the year 2002 or 2003, I don't remember exactly. I was on my third or last year as an undergrad student in Biology. My good friend, who was also a biology student at a different university in Bogotá, was part of a journal/research club and one day he showed me this paper that he had come across for some reason:

Carrell TG, Tyryshkin AM, and Dismukes GC. (2002) An evaluation of structural models for the photosynthetic water-oxidizing complex derived from spectroscopic and X-ray diffraction signatures. Journal of Biological Inorganic Chemistry 7: 2-22.

This was a minirivew discussing possible structural models of the manganese cluster of Photosystem II. Way to advanced for me to understand much of it at the time. However, one of the things that hooked me at the time was the chemical reaction the Photosystem II catalyzes: the oxidation of two water molecules to oxygen, electrons, and protons. It all seemed so mysterious and sophisticated. I was then forever captivated by the subject...

Back in 2002, only one structure of Photosystem II was available at low resolution, 3.8 A. So, the manganese cluster was just a blob... see the figure below.

From Carrell et al., 2002. Panels A and B were from the crystal structure of Zouni et al 2001. C, D and E, were possible models that were considered at the time. 

In 2011 a remarkable improvement on the structure of Photosystem II was published at 1.9 A. For the first time, each atom in the manganese cluster was resolved. See the figure below:

From Umena et al., 2011. This is how the structure of the Mn cluster of Photosystem II looks like today.

Now, I want to know how and when Photosystem II and its fascinating chemistry originated for the first time! If you're interested, check out my research!