Backbone Brackets and Arginine Tweezers delineate Class I and Class II aminoacyl tRNA synthetases

• DOI: 10.1371/journal.pcbi.1006101
• Publication Date: 2018-04-16T17:31:25Z
• Authors: Florian Kaiser; Sebastian Bittrich; Sebastian Salentin; Christoph Leberecht; V. Joachim Haupt; Sarah Krautwurst; Michael Schroeder; Dirk Labudde
• Keywords: Amino Acyl-tRNA Synthetases; Amino Acyl-tRNA Synthetases; Sequence (biology)

The origin of the machinery that realizes protein biosynthesis in all organisms is still unclear. One key component this are aminoacyl tRNA synthetases (aaRS), which ligate tRNAs to amino acids while consuming ATP. Sequence analyses revealed these enzymes can be divided into two complementary classes. Both classes differ significantly on a sequence and structural level, feature different reaction mechanisms, occur diverse oligomerization states. one unifying aspect both their function binding We identified Backbone Brackets Arginine Tweezers as most compact ATP motifs characteristic for each Class. Geometric analysis shows rearrangement upon binding, indicating general mechanism Class I structures. Regarding aaRS, Rodin-Ohno hypothesis states peculiar nature aaRS result primordial forms, called Protozymes, being encoded opposite strands same gene. were traced back proposed Protozymes more efficient successors, Urzymes. observed pairs residues contemporary structures it seems time addition, indicated by placement ancient coincides with evolutionary trace Proto-