"A journey from an ancient finger print of Rossmann fold enzymes utilizing different ribose based cofactors to the cofactor engineering of DNA methylase" Dr. Paola Laurino

Dr. Paola Laurino

Senior Postdoctoral Fellow

Department of Biological Chemistry

Weizmann Institute of Science in Rehovot, Israel

Abstract

Nucleoside-based cofactors are presumed to have preceded proteins. The Rossmann fold is one of the most ancient and functionally diverse protein folds. We analyzed an omnipresent Rossmann ribose binding interaction – a carboxylate side-chain at the tip of the second beta-strand (β2-Asp/Glu). We identified a canonical motif, defined by the β2-topology and unique geometry. This motif is uniquely found in Rossmann enzymes that use different cofactors, primarily SAM, NAD and FAD. Ribose-carboxylate bidentate interactions in other folds are not only rare but also have a different topology and geometry. Overall, these data indicate the divergence of several major Rossmann-fold enzyme classes from a common pre-Last Universal Common Ancestor (LUCA) that possessed the β2-Asp/Glu motif.
While we were studying how Rossmann fold enzyme binding ribose based cofactor evolves, the adenosine mode of binding attracted our attention. Based on this observation we started our cofactor engineering studies to remodel the catalytic site for a new cofactor. Cofactor engineering aims to obtain enzymes with novel cofactor specificities, and orthogonal recognition of a synthetic cofactor instead of the natural one. Our focus was DNA methylases a Rossmann fold protein, that uses S-adenosyl methionine (SAM) as methyl donor to methylate specific DNA target sequences. Although these enzymes play a key role as epigenetic mediators, their genomic targets are often unknown and their cellular role remains poorly understood. Our approach may provide a powerful tool to study the cellular roles of DNA methylases, including the genomic methylation patterns in cancer.

Biography

Born in Varese (Italy), Dr. Laurino received a M.Sc. in Medicinal Chemistry from Milan University in 2006. After one year research project in Leiden University (MPhil program), she started her doctoral work at ETH Zurich under the supervision of Prof. Peter H. Seeberger, and was granted a Ph.D. in Organic Chemistry in 2011.
In 2012, Dr. Laurino joined the group headed by Professor Dan S. Tawfik at Weizmann Institute of Science (Israel) in the Biological Chemistry Department as FEBS fellow. During her postdoctoral studies she had the opportunities to visit several laboratories including the group headed by Prof David Baker in Washington University and the group of Prof. Albert Jeltsch in Stuttgart University.
From October 2015, she held the position of senior Postdoctoral Fellow at Weizmann Institute of Science. She has presented her work in several meetings, including Gordon Research Conference and FEBS Congress.