Suzuki Risa, Hirakawa Hidehiko, Nagamune Teruyuki
Department of Bioengineering, School of Engineering, The University of Tokyo, Tokyo, Japan.
Biotechnol J. 2014 Dec;9(12):1573-81. doi: 10.1002/biot.201400007. Epub 2014 Jul 21.
Cytochrome P450 monooxygenases (P450s) are environmentally friendly biocatalysts that catalyze diverse chemical reactions using molecular oxygen under mild reaction conditions. P450s are activated upon receiving electrons from specific redox partner proteins, although the redox partners for most bacterial/archaeal P450s are not yet identified. Thus, it is important to establish a variety of efficient and versatile electron transfer systems from NAD(P)H to P450s for the design of biocatalysts. Sulfolobus solfataricus possesses a heterotrimeric proliferating cell nuclear antigen (PCNA). Fusion of the PCNA subunits to S. acidocaldarius P450 (CYP119) and the Pseudomonas putida redox proteins, putidaredoxin (PdX) and putidaredoxin reductase (PdR), yielded a selective protein complex containing one molecule each of the three proteins. The PCNA-mediated heterotrimerization of CYP119, PdX, and PdR enhanced the CYP119 activity, likely as a result of high local concentrations of the two redox proteins toward CYP119. Therefore, the PCNA-mediated formation of the complex containing PdX and PdR might be applicable for harnessing the utility of P450s whose redox partners are not yet identified.
细胞色素P450单加氧酶（P450s）是环境友好型生物催化剂，可在温和的反应条件下利用分子氧催化多种化学反应。P450s在从特定的氧化还原伴侣蛋白接收电子后被激活，尽管大多数细菌/古菌P450s的氧化还原伴侣尚未确定。因此，为设计生物催化剂，建立从NAD（P）H到P450s的各种高效通用的电子转移系统很重要。嗜热栖热菌拥有一种异源三聚体增殖细胞核抗原（PCNA）。将PCNA亚基与嗜酸热硫化叶菌P450（CYP119）以及恶臭假单胞菌氧化还原蛋白、恶臭假单胞菌铁氧还蛋白（PdX）和恶臭假单胞菌铁氧还蛋白还原酶（PdR）融合，产生了一种选择性蛋白复合物，其中三种蛋白各含一个分子。CYP119、PdX和PdR的PCNA介导的异源三聚化增强了CYP119的活性，这可能是由于两种氧化还原蛋白对CYP119的局部高浓度所致。因此，PCNA介导的包含PdX和PdR的复合物的形成可能适用于利用其氧化还原伴侣尚未确定的P450s的效用。
