Goat is the most preferred domesticated animal in Indian subcontinent. However, the climatic change-induced heat stress causes a formidable challenge for maintaining optimum productivity. G protein subunit alpha i3 (GNAI3) is one of the genes that may have significant role in heat tolerance mechanism in goats. The caprine GNAI3 gene was searched for homology analysis and its three dimensional protein structure was predicted followed by its validation through in silico approach. Nucleotide sequence-based phylogenetic tree analysis showed that the caprine GNAI3 gene has close evolutionary relationship with that of Ovis aries. Homology modelling of caprine GNAI3 protein was done in MODELLER 9.18 (P1), PHYRE2 (P2), GENO3D (P3) and SWISS MODEL (P4). The modelled structures were further validated after observing the Ramachandran and hydrophobicity plots. In the best of three dimensional protein structure (P4 as produced by SWISS MODEL), 330 (98.8%), three (0.9%) and one (0.3%) amino acid residues were found in favoured region, allowed region and outlier region, respectively. Degree of hydrophobicity of the generated protein structures revealed the presence of alternate hydrophobic and hydrophilic regions. The ligand receptor interaction site of the predicted 3D model was traced out using Discovery Studio 3.5. STRING database revealed protein interactions with Plcb1, Plcb2, Plcb3 and other proteins of G family such as Gnb1, Gnb2, Gnb3,Gnb4, Gng2, Gng4 and Gpsm1. KEGG pathway maps revealed interaction with eNOS, iNOS, VEGF and MAPK, which are reported to be transcribed in response to heat stress. Thus, caprine GNAI3 can be used as a possible biomarker for studying heat tolerance mechanism in goats.

中文翻译：

---

山羊GNAI3基因的综合生物信息学分析

山羊是印度次大陆最受欢迎的驯养动物。然而，气候变化引起的热应激对保持最佳生产力造成了巨大挑战。G蛋白αi3亚基（GNAI3）是可能在山羊耐热机制中发挥重要作用的基因之一。搜索山羊GNAI3基因进行同源性分析，预测其三维蛋白质结构，然后通过计算机方法对其进行验证。基于核苷酸序列的系统发育树分析表明，山羊GNAI3基因与绵羊的基因进化关系密切。在 MODELLER 9.18 (P1)、PHYRE2 (P2)、GENO3D (P3) 和 SWISS MODEL (P4) 中进行了山羊 GNAI3 蛋白的同源建模。在观察 Ramachandran 和疏水性图后，进一步验证了建模结构。在最佳三维蛋白质结构（SWISS MODEL生产的P4）中，在有利区域、允许区域和异常区域分别发现330（98.8%）、3（0.9%）和1（0.3%）个氨基酸残基. 生成的蛋白质结构的疏水性程度表明存在交替的疏水和亲水区域。使用 Discovery Studio 3.5 追踪预测的 3D 模型的配体受体相互作用位点。STRING 数据库揭示了蛋白质与 Plcb1、Plcb2、Plcb3 和 G 家族的其他蛋白质如 Gnb1、Gnb2、Gnb3、Gnb4、Gng2、Gng4 和 Gpsm1 的相互作用。KEGG 通路图揭示了与 eNOS、iNOS、VEGF 和 MAPK 的相互作用，据报道它们是响应热应激而转录的。因此，山羊 GNAI3 可作为研究山羊耐热机制的可能生物标志物。