Schäfer Friederike, Deluca Dominga, Majdic Ulrike, Kirchner Joachim, Schliwa Manfred, Moroder Luis, Woehlke Günther
Adolf Butenandt Institute, Cell Biology, University of Munich, Schillerstrasse 42, D-80336 Munich, Germany.
EMBO J. 2003 Feb 3;22(3):450-8. doi: 10.1093/emboj/cdg036.
The neck domain of fungal conventional kinesins displays characteristic properties which are reflected in a specific sequence pattern. The exchange of the strictly conserved Tyr 362, not present in animals, into Lys, Cys or Phe leads to a failure to dimerize. The destabilizing effect is confirmed by a lower coiled-coil propensity of mutant peptides. Whereas the Phe substitution has only a structural effect, the Lys and Cys replacements lead to dramatic kinetic changes. The steady state ATPase is 4- to 7-fold accelerated, which may be due to a faster microtubule-stimulated ADP release rate. These data suggest that an inhibitory effect of the fungal neck domain on the motor core is mediated by direct interaction of the aromatic ring of Tyr 362 with the head, whereas the OH group is essential for dimerization. This is the first demonstration of a direct influence of the kinesin neck region in regulation of the catalytic activity.
真菌常规驱动蛋白的颈部结构域具有一些特征性特性，这些特性反映在特定的序列模式中。动物中不存在的严格保守的酪氨酸362被赖氨酸、半胱氨酸或苯丙氨酸取代后，会导致无法二聚化。突变肽较低的卷曲螺旋倾向证实了这种去稳定作用。虽然苯丙氨酸取代仅具有结构效应，但赖氨酸和半胱氨酸取代会导致显著的动力学变化。稳态ATP酶加速了4至7倍，这可能是由于微管刺激的ADP释放速率更快。这些数据表明，真菌颈部结构域对运动核心的抑制作用是由酪氨酸362的芳香环与头部的直接相互作用介导的，而羟基对于二聚化至关重要。这是首次证明驱动蛋白颈部区域对催化活性调节有直接影响。
