The prosthetic group 4-methylideneimidazole-5-one (MIO) is the catalytic component of the ammonia lyase class of enzymes. This family is responsible for the processing of amino acids in a variety of metabolic pathways through the elimination of ammonia to form unsaturated products. Recently, new chemistry has been attributed to this family with the discovery of MIO-based aminomutases. The mechanism of electrophilic chemistry catalyzed by MIO-based enzymes has been investigated for several decades. Recent X-ray crystal structures of members of the family have provided novel insight into the molecular basis for catalysis and substrate recognition. In addition, the inclusion of aminomutases in natural product biosynthetic pathways has spurned recent advances toward rational engineering and chemoenzymatic applications.

中文翻译：

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含有4-亚甲基咪唑-5-酮的酶的结构和化学性质。

人工取代的4-甲基亚甲基咪唑-5-酮（MIO）是氨裂解酶类别的酶的催化成分。该家族负责通过消除氨形成不饱和产物来处理各种代谢途径中的氨基酸。最近，随着基于MIO的氨基变位酶的发现，新化学已归因于该家族。基于MIO的酶催化的亲电化学机理已经研究了数十年。该家族成员的最新X射线晶体结构为催化和底物识别的分子基础提供了新颖的见解。另外，在天然产物的生物合成途径中包括氨基变位酶已经刺激了最近在合理工程和化学酶学应用方面的进展。