Malik Zulfiqar A, Allen Christopher C R, Gakhar Lokesh, Lipscomb David A, Larkin Michael J, Ramaswamy S
Department of Biochemistry, The University of Iowa, Iowa City, IA 52242, USA.
Acta Crystallogr D Biol Crystallogr. 2002 Dec;58(Pt 12):2173-4. doi: 10.1107/s0907444902016803. Epub 2002 Nov 23.
The three-component naphthalene dioxygenase (NDO) enzyme system carries out the first step in the aerobic degradation of naphthalene to (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene by Rhodococcus sp. strain NCIMB 12038. The terminal oxygenase component (naphthalene 1,2-dioxygenase) that catalyzes this reaction belongs to the aromatic ring hydroxylating dioxygenase family and has been crystallized. These enzymes utilize a mononuclear non-heme iron centre to catalyze the addition of dioxygen to their respective substrates. In this reaction, two electrons, two protons and a dioxygen molecule are consumed. The Rhodococcus enzyme has only 33 and 29% sequence identity to the corresponding alpha- and beta-subunits of the NDO system of Pseudomonas putida NCIMB 9816-4, for which the tertiary structure has been reported. In order to determine the three-dimensional structure of the Rhodococcus NDO, diffraction-quality crystals have been prepared by the hanging-drop method. The crystals belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 87.5, b = 144, c = 185.6 A, alpha = beta = gamma = 90 degrees, and diffract to 2.3 A resolution.
由红球菌属菌株NCIMB 12038产生的三组分萘双加氧酶（NDO）酶系统，在萘的需氧降解过程中，将萘第一步降解为（+）-顺式-（1R，2S）-二羟基-1,2-二氢萘。催化该反应的末端加氧酶组分（萘1,2-双加氧酶）属于芳香环羟化双加氧酶家族，并且已经结晶。这些酶利用单核非血红素铁中心来催化将双加氧添加到各自的底物上。在该反应中，消耗两个电子、两个质子和一个双加氧分子。红球菌酶与恶臭假单胞菌NCIMB 9816-4的NDO系统相应的α-和β-亚基的序列同一性仅为33%和29%，其三级结构已被报道。为了确定红球菌NDO的三维结构，已通过悬滴法制备了衍射质量的晶体。这些晶体属于空间群P2(1)2(1)2(1)，晶胞参数a = 87.5，b = 144，c = 185.6 Å，α = β = γ = 90°，并衍射至2.3 Å分辨率。
