Gschwind R M, Gemmecker G, Leutner M, Kessler H, Gutknecht R, Lanz R, Flükiger K, Erni B
Institut für Organische Chemie und Biochemie II, Technische Universität München, Germany.
FEBS Lett. 1997 Mar 3;404(1):45-50. doi: 10.1016/s0014-5793(97)00084-7.
The mannose transporter of the Escherichia coli bacterial phosphotransferase system consists of three subunits: IIAB, IIC and IID. IIABMan transfers phosphoryl groups to the transported substrate via phosphohistidine intermediates. Its IIB domain was overexpressed and isotopically labelled with 13C, 15N and 2H. Heteronuclear 3D triple-resonance NMR experiments combined with a semi-automatic assignment procedure yielded the sequential assignment of the 1H, 13C and 15N backbone resonances. Based on the evaluation of conformationally sensitive parameters, the secondary structure of the IIBMan domain has been determined as an alpha/beta twisted open-sheet structure consisting of a six-stranded parallel beta-sheet with the novel strand order 3-2-4-1-5-6, six helices and a short two-stranded antiparallel beta-sheet.
IIAB、IIC和IID。IIABMan通过磷酸组氨酸中间体将磷酸基团转移到被转运的底物上。其IIB结构域被过量表达并用13C、15N和2H进行同位素标记。异核3D三重共振NMR实验结合半自动归属程序实现了1H、13C和15N主链共振的序列归属。基于对构象敏感参数的评估，IIBMan结构域的二级结构已被确定为一种α/β扭曲开放片层结构，由具有新颖链序3-2-4-1-5-6的六链平行β-折叠、六个螺旋和一个短的双链反平行β-折叠组成。
