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Ubarretxena-Belandia, I.

Publications and source records attributed to Ubarretxena-Belandia, I..

2 recordsLinked to original sources

Discovering Secondary Protein Structures via Local Euler Curvature

Protein structure analysis and classification, which is fundamental for predicting protein function, still poses formidable challenges in the fields of molecular biology, mathematics, physics and computer science. In the present work we exploit recent advances in computational topology to define a new intrinsic unsupervised topological fingerprint for proteins. These fingerprints, computed via Local Euler Curvature (LECs), identify secondary protein structures, such as Helices and Sheets, by capturing their distinctive topological signatures. Using an extensive protein residue database, the proposed computational framework not only distinguishes between structural classes via unsupervised clustering but also achieves remarkable accuracy in classifying proteins structures through supervised machine learning classifier. We also show that the internal structure of LEC space embeds the information about the secondary structure of proteins. Beyond its immediate implications for the advancement of critical application areas such as drug design and biotechnology, our approach opens a fascinating avenue towards characterizing the multiscale structures of diverse biopolymers based solely on their geometric and topological attributes.

biochemistry↗

A synthetic CRISPR-Cas nuclease with expanded enzymatic activities

Clustered regularly interspaced short palindromic repeats (CRISPR)-associated endonucleases have revolutionized biotechnology for their potential as programmable genome editors. Yet, most natural nucleases and their variants have limitations. Here, we report a fully synthetic CRISPR-associated (Cas) nuclease (-synCas) designed by Ancestral Sequence Reconstruction (ASR) that displays a set of robust and distinct targeting properties, not found in any other known CRISPR-Cas Class 2 system. We show that -synCas is a PAMless nuclease able to catalyse RNA-guided, specific cleavage of dsDNA, ssDNA and ssRNA. The synthetic enzyme is also capable of sequence-nonspecific degradation of dsDNA, ssDNA and ssRNA following activation by complementary dsDNA, ssDNA and ssRNA targets. Furthermore, -synCas exhibits a robust genome editing activity in human cells and bacteria. Cryo-electron microscopy structures of -synCas ternary and quaternary complexes provide a framework to understand the structural basis for its expanded enzymatic activities. The capability for programmable multimodal targeting of virtually any nucleic acid sequence distinguishes -synCas as a promising new tool to extend current CRISPR-based technologies.

molecular biology↗