Structure of the 5′ untranslated region in SARS-CoV-2 genome and its specific recognition by innate immune system via the human oligoadenylate synthase 1

2 '-5 '-Oligoadenylate synthetase 1 (OAS1) is one of the key enzymes driving the innate immune system response to SARS-CoV-2 infection whose activity has been related to COVID-19 severity. OAS1 is a sensor of endogenous RNA that triggers the 2 '-5 '-oligoadenylate/RNase L pathway. Upon SARS-CoV-2 infection, OAS1 is responsible for the recognition of viral RNA and has been shown to possess a particularly high sensitivity for the 5 '-untranslated (5 '-UTR) RNA region, which is organized in a double-strand stem loop motif (SL1). Here we report the structure of the SL1/OAS1 complex also rationalizing the high affinity for OAS1.

Automated summary

OAS1 is a key enzyme driving the immune response to SARS-CoV-2 infection, recognizing viral RNA and triggering the immune reaction. It has been found to have high sensitivity to the 5'-UTR region of the virus and the structure of the SL1/OAS1 complex has been elucidated, explaining its high affinity for OAS1.