O proteoma estrutural anterior ao último ancestral universal comum e suas implicações para a evolução das primeiras proteínas

Abstract

The origin and evolution of the first living beings is a great challenge for modern biology. The comprehension of the constitution of organisms on the emergence of life is an important step to understand the initial organization of the biological system. Here, we analyzed the structural proteome before the Last Universal Common Ancestor (LUCA) based in the reconstruction of the ancestral sequences and structures of proteins involved in the carbon pathways. The results indicate that the catalytic site could have been the first part of these initial proteins, which carried basic function such as binding to cofactors. With the accretion of the new parts in the structure, the catalytic function emerged. Also it is suggested that the initial structural motifs could have participated in the emergence of the proteins that work in the modern organisms. The origin of the first genes is discussed and it is suggested that the initial biological information had origin from proto-tRNAs during the formation of the primitive translation system.