Present review provides a thorough insight on some significant aspects of CHSs over a period of about past three decades with a better outlook for future studies toward comprehending the structural and mechanistic intricacy of this symbolic enzyme. Polyketide synthases (PKSs) form a large family of iteratively acting multifunctional proteins that are involved in the biosynthesis of spectrum of natural products. They exhibit remarkable versatility in the structural configuration and functional organization with an incredible ability to generate different classes of compounds other than the characteristic secondary metabolite constituents. Architecturally, chalcone synthase (CHS) is considered to be the simplest representative of Type III PKSs. The enzyme is pivotal for phenylpropanoid biosynthesis and is also well known for catalyzing the initial step of the flavonoid/isoflavonoid pathway. Being the first Type III enzyme to be discovered, CHS has been subjected to ample investigations which, to a greater extent, have tried to understand its structural complexity and promiscuous functional behavior. In this context, we vehemently tried to collect the fragmented information entirely focussed on this symbolic enzyme from about past three–four decades. The aim of this review is to selectively summarize data on some of the fundamental aspects of CHSs viz, its history and distribution, localization, structure and analogs in non-plant hosts, promoter analyses, and role in defense, with an emphasis on mechanistic studies in different species and vis-à-vis mutation-led changes, and evolutionary significance which has been discussed in detail. The present review gives an insight with a better perspective for the scientific community for future studies devoted towards delimiting the mechanistic and structural basis of polyketide biosynthetic machinery vis-à-vis CHS.

中文翻译：

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查尔酮合酶 (CHS)：象征性的 III 型聚酮化合物合酶

本综述对过去 30 年中 CHS 的一些重要方面提供了透彻的了解，为未来研究理解这种象征性酶的结构和机械复杂性提供了更好的前景。聚酮化合物合酶 (PKS) 形成了一个大家族的迭代作用多功能蛋白质，这些蛋白质参与天然产物谱的生物合成。它们在结构配置和功能组织方面表现出显着的多功能性，具有令人难以置信的能力，可以生成除特征性次生代谢物成分之外的不同类别的化合物。在架构上，查尔酮合酶 (CHS) 被认为是 III 型 PKS 的最简单代表。该酶是苯丙烷类生物合成的关键酶，并且以催化类黄酮/异黄酮途径的初始步骤而闻名。作为第一个被发现的 III 型酶，CHS 已经过大量研究，在更大程度上试图了解其结构复杂性和混杂的功能行为。在这种情况下，我们强烈地试图收集大约过去三到四年的零碎信息，这些信息完全集中在这种象征性的酶上。本综述的目的是选择性地总结 CHS 的一些基本方面的数据，即其历史和分布、定位、非植物宿主中的结构和类似物、启动子分析以及在防御中的作用，重点是机制研究在不同的物种中和相对于突变导致的变化，以及已经详细讨论过的进化意义。本综述为科学界提供了一个更好的视角，为未来致力于界定聚酮化合物生物合成机械相对于 CHS 的机制和结构基础的研究提供了一个更好的视角。