The distribution of all peptidase homologues across all phyla of organisms was analysed to determine within which kingdom each of the 271 families originated. No family was found to be ubiquitous and even peptidases thought to be essential for life, such as signal peptidase and methionyl aminopeptides are missing from some clades. There are 33 peptidase families common to archaea, bacteria and eukaryotes and are assumed to have originated in the last universal common ancestor (LUCA). These include peptidases with different catalytic types, exo- and endopeptidases, peptidases with different tertiary structures and peptidases from different families but with similar structures. This implies that the different catalytic types and structures pre-date LUCA. Other families have had their origins in the ancestors of viruses, archaea, bacteria, fungi, plants and animals, and a number of families have had their origins in the ancestors of particular phyla. The evolution of peptidases is compared to recent hypotheses about the evolution of organisms.

中文翻译：

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肽酶的起源。

分析了所有肽菌在所有生物门上的所有肽酶同源物的分布，以确定271个科中的每个家族都起源于哪个王国。没有发现一个家族普遍存在，甚至认为肽酶是生命必不可少的，例如某些进化枝中缺少信号肽酶和甲硫氨酰氨基肽。古细菌，细菌和真核生物共有33个肽酶家族，假定它们起源于最后一个普遍祖先（LUCA）。这些包括具有不同催化类型的肽酶，外切和内肽酶，具有不同三级结构的肽酶和来自不同家族但具有相似结构的肽酶。这意味着，不同的催化类型和结构早于LUCA。其他家庭起源于病毒，古细菌，细菌，真菌，植物和动物，以及许多家庭都起源于特定门的祖先。将肽酶的进化与有关生物进化的最新假说进行了比较。