Thanks to an EMBO grant, he then established himself in 1981 at the Institute of Molecular and Cellular Biology of the Centre national de la recherche scientifique (IBMC-CRNS), affiliated with the Université Louis Pasteur (ULP-Strasbourg) in France.

From 2003 to 2007 he was chairman of the Research Commission of the Faculty of Life Sciences of Louis Pasteur University, where he was an elected member of the Scientific Council from 2002-2006.

This set of rules and constraints, which can be read from sequence alignments and manipulated by computer, allows them to deduce RNA architectures, which is essential for our understanding of the function and structural evolution of RNAs.

Eric Westhof has extended his physico-chemical, structural and dynamic studies of RNAs to functional and evolutionary aspects, as well as to the prediction of strong and specific molecular interactions with molecules of therapeutic interest.

Recently, with Marat and Gula Yusupov and their collaborators, a detailed understanding of decoding errors due to tautomeric forms of the pairs between G and U has been demonstrated.

In 1984, Eric Westhof and Marc van Regenmortel's team demonstrated a correlation that proved to be central in immunochemistry: antigen epitopes generally have greater mobility than the less immunogenic regions of proteins.

In addition, several defined suites of non-Watson-Crick base pairs assemble into RNA modules that form recurrent, rather regular, building blocks of the tertiary architecture of folded RNAs.

[15] These observations set therefore limits and constraints to geometric selection in molecular recognition of complementary Watson-Crick pairs for fidelity in replication and translation processes.

We present an integrative view all the complex interaction networks between mRNA, tRNA, and rRNA : the intrinsic stability of codon-anticodon trimers, the spatial conformation of the anticodon stem-loop of tRNA, the presence of modified nucleotides, the occurrence of non-Watson-Crick pairs in the codon-anticodon helix and the interactions with bases of rRNA at the decoding site.

[16] The advantage of integrating data in this circular decoding system is that all tRNA sequence variations can be visualized, within an internal structural and energy framework, for each organism and anticodon.

Within this new representation, the multiplicity and complexity of nucleotide modifications, especially at positions 34 and 37 of the anticodon loop, segregate meaningfully and correlate well with the necessity to stabilize AU-rich codon-anticodon pairs and to avoid miscoding in split codon boxes.

This allows for a great diversity of codon usage depending on GC content of the genome and on the number and types of tRNAs.