Conserved signal peptide recognition systems across the prokaryotic domains.
Conserved signal peptide recognition systems across the prokaryotic domains.
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DOI：
10.1021/bi201852d
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发表时间：
2012-02-28
期刊：
影响因子：
2.9
通讯作者：
Sargent, Frank
中科院分区：
文献类型：
--
作者：
Coulthurst, Sarah J.;Dawson, Alice;Hunter, William N.;Sargent, Frank
双精氨酸易位（达特）途径是在细菌、古细菌和叶绿体中发现的蛋白质靶向系统。蛋白质通过含有SRRxFLK“双精氨酸”氨基酸基序的N-末端信号肽导向达特易位酶。达特系统的关键特征是其能够将完全折叠的蛋白质运输穿过离子密封膜。由于这个原因，达特途径已经进化为组装胞质外氧化还原酶，这些酶必须结合辅因子，因此在输出之前折叠。重要的是，只有辅因子加载，折叠前体的出口，并已出土的细胞过程，调节信号肽的活性。一种称为“达特校正”的机制涉及特异性信号肽结合蛋白或分子伴侣。典型的达特校对分子伴侣属于TorD家族，其致力于在细菌中组装依赖于氘的氧化还原酶。在这里，一个基因簇被确定在古生菌archaeoglobus fulgidus，预计编码一个假定的依赖于腺嘌呤的连四硫酸还原酶。该基因簇还编码TorD家族伴侣蛋白（AF 0160或TtrD），并且在这项工作中，TtrD显示出与连四硫酸盐还原酶的TtrA亚基的达特信号肽特异性结合。此外，TtrD的3D晶体结构以1.35 μ m的分辨率呈现，并且在TtrA信号肽内靠近双精氨酸靶向基序鉴定了TtrD的9个残基结合表位。这项工作表明，古细菌可能采用一种分子伴侣依赖的达特校对系统，这是类似的细菌利用。
The twin-arginine translocation (Tat) pathway is a protein targeting system found in bacteria, archaea, and chloroplasts. Proteins are directed to the Tat translocase by N-terminal signal peptides containing SRRxFLK “twin-arginine” amino acid motifs. The key feature of the Tat system is its ability to transport fully folded proteins across ionically sealed membranes. For this reason the Tat pathway has evolved for the assembly of extracytoplasmic redox enzymes that must bind cofactors, and so fold, prior to export. It is important that only cofactor-loaded, folded precursors are presented for export, and cellular processes have been unearthed that regulate signal peptide activity. One mechanism, termed “Tat proofreading”, involves specific signal peptide binding proteins or chaperones. The archetypal Tat proofreading chaperones belong to the TorD family, which are dedicatedto the assembly of molybdenum-dependent redox enzymes in bacteria. Here, a gene cluster was identified in the archaeon Archaeoglobus fulgidusthat is predicted to encode a putative molybdenum-dependent tetrathionate reductase. The gene cluster also encodes a TorD family chaperone (AF0160 or TtrD) and in this work TtrD is shown to bind specifically to the Tat signal peptide of the TtrA subunit of the tetrathionate reductase. In addition, the 3D crystal structure of TtrD is presented at 1.35 Å resolution and a nine-residue binding epitope for TtrD is identified within the TtrA signal peptide close to the twin-arginine targeting motif. This work suggests that archaea may employ a chaperone-dependent Tat proofreading system that is similar to that utilized by bacteria.
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DOI：
10.1107/s0907444905036693
发表时间：
2006-01-01
影响因子：
2.2
作者：
Evans, P
通讯作者：
Evans, P
通过大肠杆菌tat机械运输需要两个电势依赖性步骤。
影响因子：
7.8
作者：
Bageshwar, Umesh K.;Musser, Siegfried M.
通讯作者：
Musser, Siegfried M.
影响因子：
3.6
作者：
Hensel, M;Hinsley, AP;Berks, BC
通讯作者：
Berks, BC
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
11.4
作者：
Cristóbal, S;de Gier, JW;von Heijne, G
通讯作者：
von Heijne, G