The L-L oligomerization domain resides at the very N-terminus of the Sendai virus L RNA polymerase protein
The L-L oligomerization domain resides at the very N-terminus of the Sendai virus L RNA polymerase protein
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DOI：
10.1016/s0042-6822(03)00342-8
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发表时间：
2003-09-01
期刊：
影响因子：
3.7
通讯作者：
Moyer, SA
中科院分区：
文献类型：
--
作者：
Çevik, B;Smallwood, S;Moyer, SA
仙台病毒核糖核酸聚合酶由L蛋白和P蛋白组成。我们以前证明了L蛋白具有基因内互补作用，并形成一种寡聚体，其中L-L相互作用位点映射到蛋白质的N端一半(S.Smallwood等人，2002年，病毒学，00000-000)。我们现在发现，L的寡聚不依赖于P蛋白，从氨基酸(AA)1-1146到AA1-174的L的N端逐渐变小的片段都与野生型L结合，结合L的C端截断可以弥补AN379突变的L的转录缺陷，尽管这些L截断突变体不结合P。L的片段包括AA1-895，而且，AA1-189和AA1-734的N端缺失虽然仍与C蛋白结合，但已丧失形成L-L复合体和L-P复合体的能力。这些数据与位于AA1-174的L-L相互作用点是一致的。L N端347aa的定点突变取消了P结合，不影响L-L复合体的形成，因此，虽然L的L和P结合位点重叠，但它们是由不同的氨基酸介导的。L与AA1-424、AA1-381、AA1-174的N-末端部分弥补了L AA77-81突变株的转录缺陷，说明L与L的相互作用是有功能的。(C)2003年埃尔塞维尔科学公司(美国)。版权所有。
The Sendai virus RNA-dependent RNA polymerase is composed of the L and P proteins. We previously showed that the L protein gives intragenic complementation and forms an oligomer where the L-L interaction site mapped to the N-terminal half of the protein (S. Smallwood et al., 2002, Virology, 00, 000-000). We now show that L oligomerization does not depend on P protein and progressively smaller N-terminal fragments of L from amino acids (aa) 1-1146 through aa 1-174 all bind wild-type L. C-terminal truncations up to aa 424, which bind L, can complement the transcription defect in an L mutant altered at an 379, although these L truncation mutants do not bind P. The fragment of L comprising aa 1-895, furthermore, acts as a dominant-negative mutant to inhibit transcription of wild-type L. N-terminal deletions of aa 1-189 and aa 1-734 have lost the ability to form the L-L complex as well as the L-P complex, although they still bind C protein. These data are consistent with the L-L interaction site residing in aa 1-174. Site-directed mutations in the N-terminal 347 aa, of L which abolish P binding, do not affect L-L complex formation, so while the L and P binding sites on L are overlapping they are mediated by different amino acids. The N-terminal portions of L with aa 1-424, aa 1-381, and to a lesser extent aa 1-174, Call complement the transcription defect in an L mutant altered at aa 77-8 1, showing their L-L interaction is functional. (C) 2003 Elsevier Science (USA). All rights reserved.