时间：2019年9月12日（周四）下午16:00-17:00
　　Time：4:00-5:00 PM, Thursday, Sep 12, 2019
　　地点：西湖大学云栖校区5号楼一楼学术报告厅
　　Venue:Lecture Hall, 1F, Building 5, Yunqi Campus
　　主持人：西湖大学生命科学学院讲席教授 施一公
　　Host:Yigong Shi, Chair Professor of School of Life Sciences, Westlake University

　　主讲人/Speaker：Dr. Eric Westhof, Member of French Academy of Sciences, Emeritus Professor at the University of Strasbourg

　　Professor Eric Westhof is the world-renowned biophysicist, member of the French Academy of Sciences, the German Academy of Sciences, the European Academy of Sciences, member of European Molecular Biology Organization (EMBO) and professor of the University of Strasbourg, France. Prof. Eric Westhof, is currently Delegate for Teaching and Formation at the French Academy of Sciences. His long-term commitment to the study of the correlation of RNA sequences, structures and evolution has earned him an extremely high international reputation in the field of nucleic acid research. He conducted research on the kinetics and catalytic function of nucleic acids, particularly RNA, through crystallography and bioinformatics methods. He has published more than 300 papers, with more than 400 ISI-quotations, a citation rate of more than 25,000, and an H-index of 83. He was awarded the Medal of the French Society of Biochemistry and Molecular Biology in 2014; he was awarded the Lifetime Achievement Award by RNA Society in 2016. In 2018, he was awarded "Rolf-SAMMET-Gast professor" by the Aventis Foundation of Frankfurt University.

　　讲座摘要/Abstract:
　　Decoding during ribosomal translation occurs through complex and interdependent molecular recognition networks between mRNA, tRNA, and rRNA. Among those, the stability of codon-anticodon triplets, the fold of the tRNA anticodon hairpin, the modified nucleotides, and the interactions with rRNA bases at the decoding site constitute key contributors. On the basis of biochemical and genetic data in the literature, coupled with many crystal structures of fully active ribosomes, nucleotide modifications at positions 34 and 37 of the anticodon loop are now understood molecularly. Both pre-organize the anticodon loop for efficient mRNA binding. The modifications at 37 stabilize AU-rich codon-anticodon pairs and maintain the coding frame. The modifications at 34 help to avoid miscoding and allow to decode purine-ending codons in split codon boxes by promoting base pairing that can be accommodated within the structural constraints of the ribosomal grip at the decoding site.

　　Depending on the codon box, the tRNA modifications allow for diversity in codon usage depending on genomic GC content as well as on the number and types of isoacceptor tRNAs. Although universal, the genetic code is not translated identically and differences exist not only between organisms in the three kingdoms of life but also between cellular types. To decipher diversely but efficiently the genetic code, cells developed sophisticated arrays between tRNA pools and tRNA modifications, anchored in the cellular metabolic enzymatic pathways and guaranteeing protein homeostasis. Examples of mutations leading to specific human diseases in some of those enzymes will be described.

　　讲座联系人/Contact:
　　科技合作部 沈老师
　　shenxiaolian@westlake.edu.cn