The crystal structure of Trz1, the long form RNase Z from yeast

作者：Ma Miao; de la Sierra Gallay Ines Li; Lazar Noureddine; Pellegrini Olivier; Durand Dominique; Marchfelder Anita; Condon Ciaran; van Tilbeurgh Herman^*

来源：Nucleic Acids Research, 2017, 45(10): 6209-6216.

DOI：10.1093/nar/gkx216

tRNAs are synthesized as precursor RNAs that have to undergo processing steps to become functional. Yeast Trz1 is a key endoribonuclease involved in the 3' maturation of tRNAs in all domains of life. It is a member of the beta-lactamase family of RNases, characterized by an HxHxDH sequence motif involved in coordination of catalytic Zn-ions. The RNase Z family consists of two subfamilies: the short (250-400 residues) and the long forms (about double in size). Short form RNase Z enzymes act as homodimers: one subunit embraces tRNA with a protruding arm, while the other provides the catalytic site. The long form is thought to contain two fused beta-lactamase domains within a single polypeptide. Only structures of short form RNase Z enzymes are known. Here we present the 3.1 angstrom crystal structure of the long-form Trz1 from Saccharomyces cerevisiae. Trz1 is organized into two beta-lactamase domains connected by a long linker. The N-terminal domain has lost its catalytic residues, but retains the long flexible arm that is important for tRNA binding, while it is the other way around in the C-terminal domain. Trz1 likely evolved from a duplication and fusion of the gene encoding the monomeric short form RNase Z.

• 出版日期2017-6-2
• 单位中国地震局