Amidases (EC 3. 5. 1. X) are versatile biocatalysts for synthesis of chiral carboxylic acids, α-amino acids and amides due to their hydrolytic and acyl transfer activity towards the C-N linkages. They have been extensively exploited and studied during the past years for their high specific activity and excellent enantioselectivity involved in various biotechnological applications in pharmaceutical and agrochemical industries. Additionally, they have attracted considerable attentions in biodegradation and bioremediation owing to environmental pressures. Motivated by industrial demands, crystallographic investigations and catalytic mechanisms of amidases based on structural biology have witnessed a dramatic promotion in the last two decades. The protein structures showed that different types of amidases have their typical stuctural elements, such as the conserved AS domains in signature amidases and the typical architecture of metal-associated active sites in acetamidase/formamidase family amidases. This review provides an overview of recent research advances in various amidases, with a focus on their structural basis of phylogenetics, substrate specificities and catalytic mechanisms as well as their biotechnological applications. As more crystal structures of amidases are determined, the structure/function relationships of these enzymes will also be further elucidated, which will facilitate molecular engineering and design of amidases to meet industrial requirements.

酰胺酶（EC 3. 5. 1. X）是通用的生物催化剂，用于合成手性羧酸，α-氨基酸和酰胺，因为它们具有水解和酰基转移到CN键的活性。在过去的几年中，由于它们的高比活性和出色的对映选择性，在制药和农用化学工业的各种生物技术应用中得到了广泛的开发和研究。另外，由于环境压力，它们在生物降解和生物修复中引起了相当大的关注。在工业需求的推动下，基于结构生物学的酰胺酶的晶体学研究和催化机理在过去的二十年中得到了极大的发展。蛋白质结构显示不同类型的酰胺酶具有其典型的结构元素，例如签名酰胺酶中保守的AS结构域，以及乙酰胺酶/甲酰胺酶家族酰胺酶中金属相关活性位点的典型结构。这篇综述概述了各种酰胺酶的最新研究进展，重点是它们的系统进化学结构基础，底物特异性和催化机理，以及它们的生物技术应用。随着确定酰胺酶的更多晶体结构，还将进一步阐明这些酶的结构/功能关系，这将有助于分子工程和酰胺酶的设计以满足工业需求。这篇综述概述了各种酰胺酶的最新研究进展，重点是它们的系统进化学结构基础，底物特异性和催化机理，以及它们的生物技术应用。随着确定酰胺酶的更多晶体结构，还将进一步阐明这些酶的结构/功能关系，这将有助于分子工程和酰胺酶的设计以满足工业需求。这篇综述概述了各种酰胺酶的最新研究进展，重点是它们的系统进化学结构基础，底物特异性和催化机理，以及它们的生物技术应用。随着确定酰胺酶的更多晶体结构，还将进一步阐明这些酶的结构/功能关系，这将有助于酰胺酶的分子工程和设计以满足工业需求。