In silico data analyses of recombinases GdDMC1A and GdDMC1B from Giardia duodenalis

Abstract

Giardia duodenalis is a worldwide protozoa known causing diarrhea in all vertebrates, humans among these. Homologous recombination is a mechanism that provides genomic stability. Two putative recombinases were identified in G. duodenalis genome: GdDMC1A and GdDMC1B. In this article, we describe the identification of conserved domains in GdDMC1A and GdDMC1B, such as: DNA binding domains (Helix-turn-helix motif, loops 1 and 2) and an ATPcap and Walker A and B motifs associated with ATP binding and hydrolysis, phylogenetic analyses among assemblages and three-dimensional structure modeling of these recombinases using bioinformatics tools. Also, experimental data is described about LD50 determination for ionizing radiation in trophozoites of G. duodenalis. Additionally, as recombinases, GdDMC1A and GdDMC1B were used to rescue a defective Saccharomyces cerevisiae Δ rad51 strain under genotoxic conditions and data is described.The data described here are related to the research article entitled “Characterization of recombinase DMC1B and its functional role as Rad51 in DNA damage repair in Giardia duodenalis trophozoites” (Torres-Huerta et al.,) [1].

Characterization of recombinase DMC1B and its functional role as Rad51 in DNA damage repair in Giardia duodenalis trophozoites

“…5 in [Torres-Huerta et al [53]): one for GdDMC1A and another one for GdDMC1B. Interestingly, in both clades, A and E assemblage form a group, consistent with previous data [31].…”

“…Additionally, from a phylogenetic tree derived from this alignment (Fig. 2 in TorresHuerta et al [53]), GdDMC1A and GdDMC1B constituted an independent cluster compared to prokaryote and eukaryote clusters, supporting its divergence. The giardial DMC1 proteins exhibited >40% (43.9% for GdDMC1A and 42.5% for GdDMC1B) of sequence identity and >50% (59.6% for GdDMC1A and 58.8% for GdDMC1B) of sequence similarity to ScRad51.…”

“…1 and Fig. 1 in Torres-Huerta et al [53]). The alignment showed that GdDMC1A and GdDMC1B contained highly conserved Walker A and B ATPase domains, loop domains for DNA binding (L1 and L2), ATPcap, HhH motif (helix-hairpin-helix), nuclear matrix binding site (NMTS), subunit rotation motif (SRM) and the protein polymerization motif (PM) (Fig.…”

“…4 in [Torres-Huerta et al [53]) where it can be seen that, except for a few amino acid residues from the amino terminus, these recombinases were very well conserved among assemblages A, B…”

“…The 50% lethal dose (LD 50 ) obtained was approximately 160 Gy ( Fig. 7 in [Torres-Huerta et al [53]). Then, we decided to work with a lower dose than the LD 50 to cause DSBs in trophozoites but no severe damage.…”