Chen P, Tsuge H, Almassy R J, Gribskov C L, Katoh S, Vanderpool D L, Margosiak S A, Pinko C, Matthews D A, Kan C C
Agouron Pharmaceuticals, San Diego, California 92121, USA.
Cell. 1996 Sep 6;86(5):835-43. doi: 10.1016/s0092-8674(00)80157-9.
Proteolytic processing of capsid assembly protein precursors by herpesvirus proteases is essential for virion maturation. A 2.5 A crystal structure of the human cytomegalovirus protease catalytic domain has been determined by X-ray diffraction. The structure defines a new class of serine protease with respect to global-fold topology and has a catalytic triad consisting of Ser-132, His-63, and His-157 in contrast with the Ser-His-Asp triads found in other serine proteases. However, catalytic machinery for activating the serine nucleophile and stabilizing a tetrahedral transition state is oriented similarly to that for members of the trypsin-like and subtilisin-like serine protease families. Formation of the active dimer is mediated primarily by burying a helix of one protomer into a deep cleft in the protein surface of the other.
疱疹病毒蛋白酶对衣壳组装蛋白前体进行蛋白水解加工对于病毒体成熟至关重要。人巨细胞病毒蛋白酶催化结构域的2.5埃晶体结构已通过X射线衍射确定。就整体折叠拓扑结构而言，该结构定义了一类新的丝氨酸蛋白酶，其催化三联体由Ser-132、His-63和His-157组成，这与其他丝氨酸蛋白酶中的Ser-His-Asp三联体不同。然而，激活丝氨酸亲核试剂和稳定四面体过渡态的催化机制与胰蛋白酶样和枯草杆菌蛋白酶样丝氨酸蛋白酶家族成员的催化机制相似。活性二聚体的形成主要是通过将一个原体的螺旋埋入另一个蛋白质表面的深裂缝中来介导的。
