Biology subjects

Sele, C.

Publications and source records attributed to Sele, C..

2 recordsLinked to original sources

bioRxiv2023

Oligomeric state of β-coronavirus non-structural protein 10 stimulators studied by OmniSEC and Small Angle X-ray Scattering

Members of the {beta}-coronavirus family such as SARS-CoV-2, SARS, and MERS have caused pandemics over the last 20 years. Future pandemics are likely and studying the coronavirus family members is necessary for their understanding and treatment. Coronaviruses possess 16 non-structural proteins, many of which are involved in viral replication and other vital functions. Non-structural protein 10 (nsp10) is an essential stimulator of nsp14 and nsp16, modulating RNA proofreading and viral RNA cap formation. Studying nsp10 of pathogenic coronaviruses is central to understanding its multifunctional role. We report the biochemical and biophysical characterisation of full-length nsp10 from MERS, SARS and SARS-CoV-2. Proteins were subjected to a combination of OmniSEC and SEC-MALS to characterise their oligomeric state. Full-length nsp10s were predominantly monomeric in solution, while truncated versions of nsp10 have a higher tendency to oligomerise. Small angle X-ray scattering (SAXS) experiments reveal a globular shape of nsp10 which is conserved in all three coronaviruses, including MERS nsp10, which diverges most from SARS and SARS-CoV-2 nsp10s. In conclusion, unbound nsp10 proteins from SARS, MERS, and SARS-CoV-2 are globular and predominantly monomeric in solution. Additionally, we describe for the first time a functional role of the C-terminus of nsp10 for tight binding to nsp14.

biochemistry↗

bioRxiv2017

The structure of SALM5 suggests a dimeric assembly for the presynaptic RPTP ligand recognition

Synaptic adhesion molecules play a crucial role in the regulation of synapse development and maintenance. Recently several families of leucine rich repeat domain containing neuronal adhesion molecules have been characterized, including netrin G-ligands, LRRTMs, and the SALM family proteins. Most of these are expressed at the excitatory glutamatergic synapses, and dysfunctions of these genes are genetically linked with cognitive disorders, such as autism spectrum disorders and schizophrenia. The SALM family proteins SALM3 and SALM5, similar to SLITRKs, have been shown to bind to the presynaptic receptor protein tyrosine phosphatase (RPTP) family ligands. Here we present the 3 [A] crystal structure of the SALM5 LRR-Ig domain construct, and biophysical studies that verify the crystallographic results. We show that both SALM3 and SALM5 extracellular domains form similar dimeric structures, in which the LRR domains form the dimer interface. Both proteins bind to the RPTP lg-domains with micromolar affinity. SALM3 shows a clear preference for RPTP-ligands with the meB splice insert. This is in accordance with previous results showing that the LRR domain is also required for the ligand binding. Our structural studies and sequence conservation analysis suggests a ligand binding site and mechanism for RPTP binding via the dimeric LRR domain region.

biochemistry↗