Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Műegyetem rkp. 3, 1111, Budapest, Hungary.
Fermentia Microbiological Ltd, Berlini út 47-49, 1049, Budapest, Hungary.
Chembiochem. 2018 Feb 16;19(4):411-418. doi: 10.1002/cbic.201700530. Epub 2018 Jan 4.
A number of class I lyase-like enzymes, including aromatic ammonia-lyases and aromatic 2,3-aminomutases, contain the electrophilic 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO) catalytic moiety. This study reveals that Pseudomonas fluorescens R124 strain isolated from a nutrient-limited cave encodes a histidine ammonia-lyase, a tyrosine/phenylalanine/histidine ammonia-lyase (XAL), and a phenylalanine 2,3-aminomutase (PAM), and demonstrates that an organism under nitrogen-limited conditions can develop novel nitrogen fixation and transformation pathways to enrich the possibility of nitrogen metabolism by gaining a PAM through horizontal gene transfer. The novel MIO enzymes are potential biocatalysts in the synthesis of enantiopure unnatural amino acids. The broad substrate acceptance and high thermal stability of PfXAL indicate that this enzyme is highly suitable for biocatalysis.
一些 I 型裂合酶样酶，包括芳香族氨裂解酶和芳香族 2,3-氨基变位酶，含有亲电的 3,5-二氢-5-亚甲基-4H-咪唑-4-酮（MIO）催化部分。本研究表明，从营养有限的洞穴中分离出的荧光假单胞菌 R124 菌株编码组氨酸氨裂解酶、酪氨酸/苯丙氨酸/组氨酸氨裂解酶（XAL）和苯丙氨酸 2,3-氨基变位酶（PAM），并表明在氮有限条件下的生物体可以开发新的氮固定和转化途径，通过水平基因转移获得 PAM，从而丰富氮代谢的可能性。新型 MIO 酶是合成对映体纯非天然氨基酸的潜在生物催化剂。PfXAL 广泛的底物接受能力和高热稳定性表明，该酶非常适合生物催化。
