I am Nguyen Tri Nhan from Vietnam and I am the first-year PhD student of Kanaya Lab, Department of Material and Life Science, Graduate School of Engineering. From November 25 to December 24 2010, I have had a very good opportunity to do my internship at the Laboratory of Protein Structure in the International Institute of Molecular and Cell Biology in Warsaw, Poland. It is one of the most modern Polish research institutes in its field.

I worked with Dr. Marcin Nowotny who is the first person successfully obtaining the crystal structure of RNase H protein complexed with an RNA/DNA substrate. Since I work with RNase H proteins for my PhD and have been trying to get the structure in complex with the substrate, it had been a great chance for me to work with Dr. Marcin.

During this time, with the discussion and suggestion from Dr. Marcin and other lab members, I have tried to crystallize my RNase H proteins in the presence of several RNA/DNA substrates. Fortunately, I have successfully crystallized one of three RNase H proteins, LC11-RNase HI, in complex with a 14 bp RNA/DNA substrate. One of the crystals diffracted to 3.2 Å resolution. The diffraction data was processed and analyzed with the kindly helping of Dr. Marcin. Although the electron density map was not fit very well to the model and hardly to refine, we could find the presence of the RNA/DNA hybrid substrate in which the RNA strand was located closely to the active site. This result is very important and meaningful to my PhD research.

What I had learnt there, about co-crystallization of RNase H protein in complex with the substrate, is brand new to me and it is a highly valuable experience which I have to thank to this internship program for giving it to me.  

There are some more valuable things I could get beside the research results. First of all, I had made several new friends in this lab. The Post-Doc Karolina, the PhD students Michal, Mirek and Gosia, all of them had taken care of me and spent lots of their time to exchange with me, about the research (their research and my research), the culture (Polish culture, Japanese culture and Vietnamese culture) and all kind of thoughts from different points of view that PhD students like us love to share. Together with other Post-Doc in the lab, they all have good grounding in protein crystallography and very supportive to me. Last but not least, I also had the chance to travel around Warsaw and learn some about the Polish culture, like visiting the Centrum, the Old town, the Royal Castle, the Warsaw Rising Museum; and trying some Polish traditional food.

It had been a very nice and fruitful trip to me I could tell.