Förster C, Krafft C, Welfle H, Gualerzi C O, Heinemann U
Forschungsgruppe Kristallographie, Max-Delbrück-Centrum für Molekulare Medizin, Robert-Rössle-Strasse 10, D-13122 Berlin, Germany.
Acta Crystallogr D Biol Crystallogr. 1999 Mar;55(Pt 3):712-6. doi: 10.1107/s0907444998014577.
Bacillus stearothermophilus translation initiation factor 2 (IF2) specifically binds initiator fMet-tRNAfMet and positions it into the ribosomal peptidyl site in the course of the initiation of protein biosynthesis. The isolated C-terminal domain of IF2 is capable of binding fMet-tRNAfMet, as shown by RNase A and hydrolysis protection experiments. In the presence of fMet-tRNAfMet, the IF2 C-domain yielded orthorhombic crystals of space group I222 (I212121) diffracting to 3.4 A resolution. The existence of equimolar amounts of tRNA and protein in the crystals was proven by Raman spectroscopy. The observed unit cell suggests the presence of two IF2 C- domain-fMet-tRNAfMet complexes per asymmetric unit of the crystal.
嗜热脂肪芽孢杆菌翻译起始因子2（IF2）在蛋白质生物合成起始过程中特异性结合起始甲酰甲硫氨酰 - tRNAfMet，并将其定位到核糖体肽基位点。如核糖核酸酶A和水解保护实验所示，分离出的IF2 C末端结构域能够结合甲酰甲硫氨酰 - tRNAfMet。在甲酰甲硫氨酰 - tRNAfMet存在的情况下，IF2 C结构域产生了空间群为I222（I212121）的正交晶体，衍射分辨率达到3.4埃。通过拉曼光谱证实了晶体中存在等摩尔量的tRNA和蛋白质。观察到的晶胞表明每个晶体不对称单元中存在两个IF2 C结构域 - 甲酰甲硫氨酰 - tRNAfMet复合物。
