Origins of the Intermediate Spectral Form in M100 Mutants of Photoactive Yellow Protein.
Origins of the Intermediate Spectral Form in M100 Mutants of Photoactive Yellow Protein.
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DOI：
10.1111/php.12464
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发表时间：
2015-07
影响因子：
3.3
通讯作者：
Woolley GA
中科院分区：
文献类型：
--
作者：
Kumar A;Woolley GA
来自嗜盐嗜盐菌的光活性黄色蛋白（PYP）的许多单位点突变体以及来自其他物种的 PYP 同源物在其暗适应状态下在吸光度最大值的短波长侧表现出肩部。这种肩部出现的结构基础，称为“中间光谱形式”，仅针对 Y42F 突变进行了详细研究。在这里，我们探讨了循环排列的 H. halophila PYP (M121E-cPYP) 的 M121E 衍生物中出现中间光谱形式的结构基础。 M121E-cPYP 中的 M121 位点对应于野生型嗜盐嗜盐菌 PYP 中的 M100 位点。使用耐盐冷冻探针进行高分辨率核磁共振测量，能够识别那些直接受氯化铵浓度增加影响的残留物，氯化铵浓度大大提高了中间光谱形式的分数。发现含有 M121E (M100E) 突变的表面环中的残基受到氯化铵以及一组离散残基的影响，这些残基通过氢键网络将该表面环与发色团的埋藏羟基连接起来。因此，表面环构象动力学的局部变化可以在埋藏的羟基发色团附近产生结构重排，同时使蛋白质中的大部分残基不受影响。
Numerous single site mutants of photoactive yellow protein (PYP) from H. halophila and as well as PYP homologs from other species exhibit a shoulder on the short wavelength side of the absorbance maximum in their dark-adapted states. The structural basis for the occurrence of this shoulder, called the “intermediate spectral form,” has only been investigated in detail for the Y42F mutation. Here we explore the structural basis for occurrence of the intermediate spectral form in a M121E derivative of a circularly permuted H. halophila PYP (M121E-cPYP). The M121 site in M121E-cPYP corresponds to the M100 site in wild-type H. halophila PYP. High resolution NMR measurements with a salt-tolerant cryoprobe enabled identification of those residues directly affected by increasing concentrations of ammonium chloride, a salt that greatly enhances the fraction of the intermediate spectra form. Residues in the surface loop containing the M121E (M100E) mutation were found to be affected by ammonium chloride as well as a discrete set of residues that link this surface loop to the buried hydroxyl group of the chromophore via a hydrogen bond network. Localized changes in the conformational dynamics of a surface loop can thereby produce structural rearrangements near the buried hydroxyl group chromophore while leaving the large majority of residues in the protein unaffected.
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影响因子：
3.1
作者：
Hospes, Marijke;Hendriks, Johnny;Hellingwerf, Klaas J.
通讯作者：
Hellingwerf, Klaas J.
影响因子：
3.4
作者：
Imamoto, Yasushi;Tatsumi, Sanae;Kataoka, Mikio
通讯作者：
Kataoka, Mikio
影响因子：
2.9
作者：
Imamoto, Y;Koshimizu, H;Tokunaga, F
通讯作者：
Tokunaga, F
影响因子：
2.9
作者：
Kyndt, JA;Hurley, JK;Van Beeumen, JJ
通讯作者：
Van Beeumen, JJ
影响因子：
3.3
作者：
Kyndt, John A.;Meyer, Terry E.;Cusanovich, Michael A.
通讯作者：
Cusanovich, Michael A.