Backbone dynamics of the Bacillus subtilis glucose permease IIA domain determined from 15N NMR relaxation measurements.
Backbone dynamics of the Bacillus subtilis glucose permease IIA domain determined from 15N NMR relaxation measurements.
复制标题
通过 15N NMR 弛豫测量确定枯草芽孢杆菌葡萄糖通透酶 IIA 结构域的骨架动力学。
DOI：
10.1021/bi00133a003
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发表时间：
1992
期刊：
影响因子：
2.9
通讯作者：
Wright,PE
中科院分区：
文献类型：
--
作者：
Stone,MJ;Fairbrother,WJ;Palmer3rd,AG;Reizer,J;SaierJr,MH;Wright,PE
Scripps研究所分子生物学系，拉霍亚，加利福尼亚州92037，和加利福尼亚大学圣地亚哥分校生物学系，拉霍亚，加州92093-0116，1991年12月28日接收摘要：用反向检测的双-荧光法表征了枯草芽孢杆菌葡萄糖通透酶的15 N标记IIA结构域的骨架动力学。三维1H-15 N NMR谱。在500 MHz的光谱仪质子频率下，测量了151个质子化骨架氮中的137个（91%）的纵向（J1）和横向（T2）15 N弛豫时间常数和稳态（J1 * H）-15N NOE。这些数据进行了分析，使用无模型动力学形式主义，以确定广义序参数（S2），有效的相关时间为内部运动（re），和15 N交换加宽的贡献（J？ex），以及总的分子旋转相关时间（rm）。大多数残基的T1和T2值分别在0.45-0.55和0.11-0.15 s范围内;然而，少数残基表现出明显较慢的弛豫。类似地，大多数残基的j* H}-15 N NOE值在0.72-0.80的范围内，但少数残基具有小得多的正NOE，并且一些残基表现出负NOE。分子旋转相关时间为6.24± 0.01ns，大部分残基的有序参数在0.75-0.90之间，Re值小于约1.00。25便士。发现比平均值更移动的残基集中在三个区域：观察到高度无序的N-末端残基（1-13）;从P25到D41的环，其顶点位于活性位点附近，可能在与其他蛋白质结合中起作用;以及从A146到S149的区域。所有移动的残基都发生在靠近末端、内环或不规则二级结构的区域。蛋白质的分子内运动，其特征时间尺度从皮秒到秒（或更长），对于酶催化、结合特异性和调节控制是重要的（威廉姆斯，1979，1989; Gurd & Rothgeb，1979; Welch et al.，1982; Karplus & McCammon，1983;班尼特& Huber，1983;林格& Petsko，1985）。NMR 1光谱学是唯一适合于表征这种内部运动;
Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, and Department of Biology, University of California at San Diego, La Jolla, California 92093-0116 Received December 28, 1991 abstract: The backbone dynamics of the uniformly 15N-labeled IIA domain of the glucose permease of Bacillus subtilis have been characterized using inverse-detected two-dimensional ‘H-15N NMR spectroscopy. Longitudinal (J,) and transverse (T2) 15N relaxation time constants and steady-state j* H)-15N NOEs were measured, at a spectrometer proton frequency of 500 MHz, for 137 (91%) of the 151 protonated backbone nitrogens. These data were analyzed by using a model-free dynamics formalism to determine the generalized order parameter (S2), the effective correlation timefor internal motions (re), and 15N exchange broadening contributions (J? ex) for each residue, as well as the overall molecularrotational correlation time (rm). The Tj and T2 values for most residues were in theranges 0.45-0.55 and 0.11-0.15 s, respectively; however, a small number of residues exhibited significantly slower relaxation. Similarly, j* H}-15N NOE values for most residues were in the range 0.72-0.80, but a few residues had much smaller positive NOEs and some exhibited negative NOEs. The molecular rotational correlation time was 6.24±0.01 ns; most residues had order parameters in the range 0.75-0.90 and re values of less than ca. 25 ps. Residues found to be more mobile than the average were concentrated in three areas: the N-terminal residues (1-13), which were observed to be highly disordered; the loop from P25 toD41, the apex of which is situated adjacent to the active site and may have a role in binding to other proteins; and the region from A146 to S149. All mobile residues occurred in regions close to termini, inloops, or in irregular secondary structure.Intramolecular motions of proteins, with characteristic time scales ranging from picoseconds to seconds (or longer), are important for enzyme catalysis, binding specificity, and reg-ulatory control (Williams, 1979, 1989; Gurd & Rothgeb, 1979; Welch et al., 1982; Karplus & McCammon, 1983; Bennett & Huber, 1983; Ringe & Petsko, 1985). NMR1 spectroscopy is uniquely suited to characterizing such internal motions;