Enzymes catalyze a vast range of reactions. Their catalytic performances, mechanisms, global folds, and active-site architectures are also highly diverse, suggesting that enzymes are shaped by an entire range of physiological demands and evolutionary constraints, as well as by chemical and physicochemical constraints. We have attempted to identify signatures of these shaping demands and constraints. To this end, we describe a bird’s-eye view of the enzyme space from two angles: evolution and chemistry. We examine various chemical reaction parameters that may have shaped the catalytic performances and active-site architectures of enzymes. We test and weigh these considerations against physiological and evolutionary factors. Although the catalytic properties of the “average” enzyme correlate with cellular metabolic demands and enzyme expression levels, at the level of individual enzymes, a multitude of physiological demands and constraints, combined with the coincidental nature of evolutionary processes, result in a complex picture. Indeed, neither reaction type (a chemical constraint) nor evolutionary origin alone can explain enzyme rates. Nevertheless, chemical constraints are apparent in the convergence of active-site architectures in independently evolved enzymes, although significant variations within an architecture are common.

中文翻译：

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酶进化的鸟瞰图：化学，物理化学和生理学考虑

酶催化各种各样的反应。它们的催化性能，机理，整体折叠和活性位点结构也高度多样，表明酶的形成受整个生理需求和进化限制以及化学和物理化学限制的影响。我们已经尝试识别出这些成型需求和约束条件的特征。为此，我们从两个角度描述了酶空间的鸟瞰图：进化和化学。我们研究了可能影响酶的催化性能和活性位点结构的各种化学反应参数。我们测试并权衡这些考虑因素与生理和进化因素。尽管“平均”酶的催化特性与细胞代谢需求和酶表达水平相关，但在单个酶的水平上，多种生理需求和限制条件以及进化过程的巧合性质导致了复杂的画面。实际上，无论是反应类型（化学约束）还是进化起源都不能单独解释酶的速率。然而，尽管结构内的显着变化是常见的，但化学限制在活性位点结构在独立进化的酶中的融合中是显而易见的。无论是反应类型（化学限制）还是进化起源都不能解释酶的速率。然而，尽管结构内的显着变化是常见的，但化学限制在活性位点结构在独立进化的酶中的融合中是显而易见的。无论是反应类型（化学限制）还是进化起源都不能解释酶的速率。然而，尽管结构内的显着变化是常见的，但化学限制在活性位点结构在独立进化的酶中的融合中是显而易见的。