Biology subjects

Torres-Larios, A.

Publications and source records attributed to Torres-Larios, A..

3 recordsLinked to original sources

bioRxiv2023

Common evolutionary origins of the bacterial glycyl tRNA synthetaseand alanyl tRNA synthetase

Aminoacyl-tRNA synthetases (aaRSs) establish the genetic code. Each aaRS covalently links a given canonical amino acid to a cognate set of tRNA isoacceptors. Glycyl tRNA aminoacylation is unusual in that it is catalyzed by different aaRSs in different lineages of the Tree of Life. We have investigated the phylogenetic distribution and evolutionary history of bacterial glycyl tRNA synthetase (bacGlyRS). This enzyme is found in early diverging bacterial phyla such as Firmicutes, Acidobacteria, and Proteobacteria, but not in archaea or eukarya. We observe relationships between each of six domains of bacGlyRS and six domains of four different RNA-modifying proteins. Component domains of bacGlyRS show common ancestry with i) the catalytic domain of class II tRNA synthetases; ii) the HD domain of the bacterial RNase Y; iii) the body and tail domains of the archaeal CCA-adding enzyme; iv) the anti-codon binding domain of the arginyl tRNA synthetase; and v) a previously unrecognized domain that we call ATL (Ancient tRNA latch). The ATL domain is found only in bacGlyRS and in the universal alanyl tRNA synthetase (uniAlaRS). Further, the catalytic domain of bacGlyRS is more closely related to the catalytic domain of uniAlaRS than to any other aminoacyl tRNA synthetase. The combined data suggest that the ATL and catalytic domains of these two enzymes are ancestral to bacGlyRS and uniAlaRS, which emerged from common protein ancestors by bricolage, stepwise accumulation of protein domains, before the last universal common ancestor of life.

evolutionary biology↗

bioRxiv2021

Ancestral protein topologies draw the rooted bacterial tree of life

Aminoacyl tRNA synthetases (aaRSs) are among the proposed proteins present in the Last Universal Common Ancestor (LUCA). There are two types of glycyl tRNA synthetases (GlyRSs), from which the archaeal-eukaryal type is the one suggested to be present in LUCA. Here we solved the crystal structure of a complete bacterial glycyl tRNA synthetase (bacGlyRS) and show that indeed, bacGlyRS carries several structural signals that point it at the origin of all aaRSs. Furthermore, if bacGlyRS is ancestral, it should help to build a reliable Tree of Life (ToL). Given the modular nature of protein evolution, we used only two sub-domain segments with duplicated ancestral topologies, no detected orthologs and an assumed limited horizontal gene transfer (HGT). These motifs correspond to the non-specific RNA binding regions of contemporary bacGlyRS, archaeal CCA-adding enzyme (arch-CCAadd), and eukaryotic rRNA processing enzyme (euk-rRNA). The calculated, rooted bacterial ToL agrees with several phyla relationships unaccounted by the available trees.

evolutionary biology↗

bioRxiv2019

The contribution of the ankyrin repeat domain of TRPV1 as a thermal module

The TRPV1 cation non-selective ion channel plays an essential role in thermosensation and perception of other noxious stimuli. TRPV1 can be activated by low pH, high temperature or naturally occurring pungent molecules such as allicin, capsaicin or resiniferatoxin. Its noxious thermal sensitivity makes it an important participant as a thermal sensor in mammals. However, details of the mechanism of channel activation by increases in temperature remain unclear. Here we used a combination of approaches to try to understand the role of the ankyrin repeat domain (ARD) in channel behavior. First, a computational modeling approach by coarse-grained molecular dynamics simulation of the whole TRPV1 embedded in a phosphatidylcholine (POPC) and phosphatidylethanolamine (POPE) membrane provides insight into the dynamics of this channel domain. Global analysis of the structural ensemble shows that the ankyrin repeat domain is a region that sustains high fluctuations during dynamics at different temperatures. We then performed biochemical and thermal stability studies of the purified ARD by means of circular dichroism and tryptophan fluorescence and demonstrate that this region undergoes structural changes at similar temperatures that lead to TRPV1 activation. Our data suggest that the ARD is a dynamic module and that it may participate in controlling the temperature sensitivity of TRPV1.\n\nStatement of SignificanceThis work demonstrates that the temperature-dependent dynamics of the ankyrin repeat domain (ARD) of TRPV1 channels, as probed by coarse-grained molecular dynamics, corresponds to the experimentally determined dynamics of an isolated ARD domain. These results show that this region of TRPV1 channels undergoes significant conformational change as a function of increased temperature and suggest that it participates in the temperature-dependent structural changes that lead to channel opening.

biophysics↗