Electron Microscopy Facility of IIT, Italy

Roberto Marotta is Chief Technician at the Electron Microscopy Facility of IIT in Genoa, Italy. He made use of EM services of the EMBL Imaging Centre in remote by shipping his samples to the facility. 

His project explores the full-length structure of a protein that is involved in cell DNA repair pathways. Indeed, no structural information on this full-length protein has been published so far. Obtaining three-dimensional information is crucial to better understand the protein mechanism of action as well as to develop potent and specific cancer-related inhibitors. 

What was the specific scientific challenge that you could overcome thanks to our service? 

Thanks to the EMBL Imaging Centre we have been able to obtain a high resolution (2.16 Å) cryo-EM electrondensity map of our protein of interest. 

Which imaging technologies in the EMBL Imaging Centre did you apply?

We have applied cryo-EM. We have performed vitrified grid screening and then an exhaustive high resolution data collection on the best identified grids for single particle image data analysis. 

Which new technique/sample preparation did you learn at the EMBL Imaging Centre and will you be able to apply it in the further course of your studies?

At the EMBL Imaging Centre, thanks to the help of Dr. Simone Mattei and Dr. Simon Fromm, we learned how to better assess and check grid vitrification quality and particle distribution during grid screening. We received advices on how to optimally use the SerialEM acquisition software during grid screening and data collection. We have also received hints on how to organize the acquired high resolution data for single particle image analysis. 

What results did you achieve using our services and could you publish those? 

We obtained a 2.16 Å cryo-EM electron density map of the protein of interest. We plan to publish as soon as possible these results as there is currently no 3D information on the structure of the full-length protein. 

How long did you stay with us and how did you like staying on site/in Heidelberg? 

All the experiments, both grid screening and high-end data collections, have been performed virtually due to the COVID-19 pandemic. Nevertheless, Dr. Simone Mattei was really helpful in evaluating our results. We could participate in remote and assist Dr. Simon Fromm in the various stages of sample screening and data collection. This experience was very helpful and instructive. 

Anything else you would like the future users of EMBL Imaging Centre to know? 

The communication with the EMBL Imaging Centre, and in particular with Dr. Simone Mattei and Dr. Simon Fromm, have been excellent. The staff at the EMBL Imaging Centre has always been very kind, supportive and helpful.