1 Bacterial glycyl tRNA synthetase offers glimpses of ancestral protein topologies Jorge-Uriel Dimas-Torres 1 , Annia Rodríguez-Hernández 1 , Marco Igor Valencia- Sánchez 1 , Eduardo Campos-Chávez 1 , Victoria Godínez-López 1 , Daniel-Eduardo Rodríguez-Chamorro 1 , Morten Grøtli 2 , Cassandra Fleming 2 , Adriana Hernández- González 1 , Marcelino Arciniega 1 , and Alfredo Torres-Larios 1 * 1 Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Apartado postal 70-243, Mexico City, 04510, México, 2 Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden. Address correspondence to: Alfredo Torres-Larios, PhD; Circuito Exterior s/n, Ciudad Universitaria. Apartado postal 70-243, México D.F. 04510, México. Fax 011-52-55-5622-5630; E- mail:torres@ifc.unam.mx. Running title Bacterial glycyl tRNA synthetase as an ancestral protein Keywords Aminoacyl tRNA synthetase, protein evolution, multifunctional protein, protein domain, protein-nucleic acid interaction, RNA binding protein, molecular evolution . CC-BY-NC-ND 4.0 International license available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made The copyright holder for this preprint this version posted August 31, 2021. ; https://doi.org/10.1101/2021.08.20.456953 doi: bioRxiv preprint