ICAR-National Institute for Plant Biotechnology, New Delhi, India.
Gujarat Biotechnology University, (GIFT)-City, Gandhinagar, Gujarat, India.
PLoS One. 2022 May 13;17(5):e0268154. doi: 10.1371/journal.pone.0268154. eCollection 2022.
Sugar transporter proteins (STPs) are membrane proteins required for sugar transport throughout cellular membranes. They plays an imperative role in sugar transmission across the plant and determinants of crop yield. However, the analysis of these important STPs Sugars Will Eventually be Exported Transporters (SWEET) family in legumes is still not well-documented and remains unclear. Therefore, the in-silico analysis of STPs has been performed to unravel their cellular, molecular, and structural composition in legume species. This study conducted a systematic search for STPs in Cajanus cajan using the Blastp algorithm to understand its molecular basis. Here, we performed a comprehensive analysis of 155 identified SWEET proteins across 12 legumes species, namely (Cajanus cajan, Glycine max, Vigna radiate, Vigna angularis, Medicago truncatula, Lupinus angustifolius, Glycine soja, Spatholobus suberectus, Cicer arietinum, Arachis ipaensis, Arachis hypogaea, Arachis duranensis). The amino acid composition and motif analysis revealed that SWEET proteins are rich in essential amino acids such as leucine, valine, isoleucine, phenylalanine, and serine while less profuse in glutamine, tryptophan, cysteine, and histidine. A total of four main conserved motifs of SWEET proteins are also highly abundant in these amino acids. The present study deciphered the details on primary physicochemical properties, secondary, tertiary structure, and phylogenetic analysis of SWEETs protein. Majorities of SWEET proteins (72.26%) are in stable form with an average instability index of 36.5%, and it comprises a higher fraction of positively charged amino acid Arg + Lys residues. Secondary structure analysis shown that these proteins are richer in alpha-helix (40%) than extended strand (30%) and random coil (25%), respectively. Furthermore, to infer their mechanism at a structural and functional level which play an essential roles in growth, development, and stress responses. This study will be useful to examine photosynthetic productivity, embryo sugar content, seed quality, and yield enhancement in Fabaceae for a sustainable source of essential amino acids and carbon source.
糖转运蛋白（STPs）是穿过细胞膜进行糖转运所需的膜蛋白。它们在植物中的糖传递中起着至关重要的作用，也是作物产量的决定因素。然而，豆类中这些重要的 Sugars Will Eventually be Exported Transporters（SWEET）家族的 STP 分析仍未得到很好的记录，其情况仍不清楚。因此，对 STP 进行了计算机分析，以揭示其在豆科植物中的细胞、分子和结构组成。本研究使用 Blastp 算法在 Cajanus cajan 中进行了 STP 的系统搜索，以了解其分子基础。在这里，我们对 12 种豆科植物中的 155 种鉴定出的 SWEET 蛋白进行了综合分析，这些植物包括（Cajanus cajan、Glycine max、Vigna radiate、Vigna angularis、Medicago truncatula、Lupinus angustifolius、Glycine soja、Spatholobus suberectus、Cicer arietinum、Arachis ipaensis、Arachis hypogaea、Arachis duranensis）。氨基酸组成和基序分析表明，SWEET 蛋白富含必需氨基酸，如亮氨酸、缬氨酸、异亮氨酸、苯丙氨酸和丝氨酸，而谷氨酰胺、色氨酸、半胱氨酸和组氨酸则较少。SWEET 蛋白的四个主要保守基序也高度富含这些氨基酸。本研究阐明了 SWEET 蛋白的初级物理化学性质、二级、三级结构和系统发育分析的详细信息。大多数 SWEET 蛋白（72.26%）处于稳定状态，平均不稳定性指数为 36.5%，并且包含较高比例的带正电荷的氨基酸精氨酸+赖氨酸残基。二级结构分析表明，这些蛋白富含α-螺旋（40%），而伸展链（30%）和无规则卷曲（25%）较少。此外，为了推断它们在结构和功能水平上的机制，这些机制在生长、发育和应激反应中起着至关重要的作用。本研究将有助于检查豆科植物的光合作用生产力、胚胎糖含量、种子质量和产量的提高，以获得必需氨基酸和碳源的可持续来源。
