Mutations in the yeast Nhp6 protein can differentially affect its in vivo functions
Mutations in the yeast Nhp6 protein can differentially affect its in vivo functions
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DOI：
10.1006/bbrc.2001.4273
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发表时间：
2001-02-09
影响因子：
3.1
通讯作者：
Kolodrubetz, D
中科院分区：
文献类型：
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作者：
Kruppa, M;Kolodrubetz, D
Nhp6A和Nhp6B来自S.酿酒酵母是在38 ℃下生存所必需的，因为它们参与RNA聚合酶III对SNR6的转录。Nhp6A还通过RNA聚合酶II抑制NHP6B的转录。Nhp6属于HMG1家族，由80个氨基酸的DNA结合结构域定义，其包括6个高度保守的残基。在Nhp6A中突变这些氨基酸，并在体内评估它们对Nhp6功能的影响。令人惊讶的是，大多数变化允许Nhp6A在38 ℃下正常发挥支持生长的功能。然而，六个突变体在体内功能有差异的影响。最后，两种在体内不能恢复Nhp6A功能的突变蛋白在体外与野生型一样能结合和弯曲DNA。总之，这些结果表明Nhp6与另一种蛋白质相互作用以执行其一些生物学功能，并且这种相互作用可能在由RNA聚合酶II与RNA聚合酶III转录的启动子处不同。(C)北京：科学出版社.
Nhp6A and Nhp6B from S. cerevisiae are required for viability at 38 degreesC because they are involved in transcription of SNR6 by RNA polymerase III. Nhp6A also represses transcription of NHP6B by RNA polymerase II. Nhp6 belongs to the HMG1 family, defined by an 80 amino acid DNA binding domain, which includes six highly conserved residues. These amino acids were mutated in Nhp6A and their affects on Nhp6 function were assessed in vivo. Surprisingly, most of the changes allowed Nhp6A to function normally in supporting growth at 38 degreesC. However, six mutants had differential effects on in vivo function. Finally, two of the mutant proteins that did not restore Nhp6A function in vivo were shown to bind and bend DNA in vitro as well as wild type. Together, these results suggest that Nhp6 interacts with another protein(s) to carry out some of its biological functions and that this interaction might differ at promoters transcribed by RNA polymerase II versus RNA polymerase III. (C) 2001 Academic Press.