Enzymatic characterization and mutational studies of TruD - the fifth family of pseudouridine synthases
Enzymatic characterization and mutational studies of TruD - the fifth family of pseudouridine synthases
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DOI：
10.1016/j.abb.2009.07.023
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发表时间：
2009-09-01
影响因子：
3.9
通讯作者：
Huang, Raven H.
中科院分区：
文献类型：
--
作者：
Chan, Chio Mui;Huang, Raven H.
伪尿嘧啶（Psi）是由一类称为伪尿嘧啶合成酶（Psi S）的酶催化尿嘧啶(U)异构化而形成的。TruD是Psi S的第五个家族，对Psi S的前四个家族（TruA, TruB， RsuA和RluA）的研究表明，保守的Asp和Tyr对催化至关重要。然而，在TruD家族中，酪氨酸并不保守。在本研究中，我们测定了大肠杆菌中TruD的酶学参数，并对一系列TruD单、双、三重突变体进行了酶学分析。我们的研究表明，一个仅在TruD家族中严格保守的Glu可能是TruD的一般碱基。与前四个家族相比，我们还提出了trud催化Psi形成的可能独特机制。(C) 2009爱思唯尔公司版权所有。
Pseudouridine (Psi) is formed through isomerization of uridine (U) catalyzed by a class of enzymes called pseudouridine synthases (Psi S). TruD is the fifth family of Psi S. Studies of the first four families (TruA, TruB, RsuA, and RluA) of Psi S reveal a conserved Asp and Tyr are critical for catalysis. However, in TruD family, the tyrosine is not conserved. In this study, we measured the enzymatic parameters for TruD in Escherichia coli, and carried out enzymatic assays for a series of single, double, and triple TruD mutants. Our studies indicate that a Glu, strictly conserved in only TruD family is likely to be the general base in TruD. We also proposed a possible distinct mechanism of TruD-catalyzed Psi formation compared to the first four families. (C) 2009 Elsevier Inc. All rights reserved.