Ubiquitin interactions of NZF zinc fingers
Ubiquitin interactions of NZF zinc fingers
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DOI：
10.1038/sj.emboj.7600114
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发表时间：
2004-04-07
期刊：
影响因子：
11.4
通讯作者：
Sundquist, WI
中科院分区：
文献类型：
--
作者：
Alam, SL;Sun, J;Sundquist, WI
泛素（Ub）在许多不同的生物学途径中发挥作用，其中它通常与含有模块化Ub识别结构域的蛋白质相互作用。一种这样的识别结构域是Npl 4锌指（NZF），其是在许多在Ub依赖性过程中起作用的蛋白质中发现的紧凑锌结合模块。我们现在报道来自Npl 4的NZF结构域与Ub复合的溶液结构。该结构揭示了围绕锌配位位点的三个关键NZF残基（13 TF 14/M-25）结合Ub的疏水性“Ile 44”表面。13 TF 14/M-25基序中的突变抑制Ub结合，并且缺乏该基序的天然存在的NZF结构域不结合Ub。然而，将13 TF 14/M-25基序取代到来自RanBP 2的非结合NZF结构域中产生了Ub结合活性，证明了NZF支架的多功能性。最后，NZF突变，抑制Ub结合的NZF结构域的Vps 36/ESCRT-II也抑制分选泛素化蛋白进入酵母液泡。因此，NZF是一个通用的蛋白质识别结构域，用于在液泡蛋白分选过程中结合泛素化蛋白，可能还有许多其他生物学过程。
Ubiquitin (Ub) functions in many different biological pathways, where it typically interacts with proteins that contain modular Ub recognition domains. One such recognition domain is the Npl4 zinc finger (NZF), a compact zinc-binding module found in many proteins that function in Ub-dependent processes. We now report the solution structure of the NZF domain from Npl4 in complex with Ub. The structure reveals that three key NZF residues (13TF14/M-25) surrounding the zinc coordination site bind the hydrophobic 'lle44' surface of Ub. Mutations in the 13TF14/M-25 motif inhibit Ub binding, and naturally occurring NZF domains that lack the motif do not bind Ub. However, substitution of the 13TF14/M-25 motif into the nonbinding NZF domain from RanBP2 creates Ub-binding activity, demonstrating the versatility of the NZF scaffold. Finally, NZF mutations that inhibit Ub binding by the NZF domain of Vps36/ESCRT-II also inhibit sorting of ubiquitylated proteins into the yeast vacuole. Thus, the NZF is a versatile protein recognition domain that is used to bind ubiquitylated proteins during vacuolar protein sorting, and probably many other biological processes.