Miernyk J A, Hayman T G
National Center for Agricultural Utilization Research, Peoria, Illinois 61604, USA.
Plant Physiol. 1996 Feb;110(2):419-24. doi: 10.1104/pp.110.2.419.
The codons for the amino acid residues making up the proposed ATP-binding sites of the maize (Zea mays L.) endoplasmic reticulum and tomato (Lycopersicon esculentum) cytoplasmic Stress70 proteins were deleted from their respective cDNAs. The deletions had little effect on the predicted secondary structure characteristics of the encoded proteins. Both wild-type and mutant proteins were expressed in Escherichia coli and purified to electrophoretic homogeneity. The mutant recombinant proteins did not bind to immobilized ATP columns, had no detectable ATPase activity, and were unable to function in vitro as molecular chaperones. Additionally, the inability to bind ATP was associated with changes in the oligomerization state of the Stress70 proteins.
构成玉米（Zea mays L.）内质网和番茄（Lycopersicon esculentum）细胞质应激70蛋白拟议的ATP结合位点的氨基酸残基密码子，从它们各自的cDNA中被删除。这些缺失对所编码蛋白质的预测二级结构特征影响很小。野生型和突变型蛋白均在大肠杆菌中表达，并纯化至电泳纯。突变型重组蛋白不与固定化的ATP柱结合，没有可检测到的ATP酶活性，并且在体外不能作为分子伴侣发挥作用。此外，无法结合ATP与应激70蛋白的寡聚化状态变化有关。
