Kdp, a bacterial P-type ATPase whose expression and activity are regulated by turgor pressure.
Kdp, a bacterial P-type ATPase whose expression and activity are regulated by turgor pressure.
复制标题
DOI：
--
复制
发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Wolfgang Epstein
中科院分区：
文献类型：
--
作者：
Wolfgang Epstein
Kdp ATP酶是一种P型ATP酶，由三个大的蛋白质亚基组成，每个亚基可能含有2个拷贝。一个小的疏水肽，编码在同一操纵子作为大亚基，也可能参与。Kdp对K+具有非常高的亲和力，并且在其浓度低时用于吸附该离子。Kdp在两个水平上对膨压作出反应，即活动水平和表达水平。当膨压低时，Kdp介导净摄取，而当膨压正常时，Kdp介导交换而无净变化。Kdp仅在膨压低时表达。这种控制是由一对调节蛋白介导的，它们是广泛分布于细菌中的“传感器-效应器”调节剂的成员。这表明，低膨压改变的KdpD的“传感器”蛋白的构象，激活其假定的激酶活性磷酸化KdpE，“效应器”蛋白，磷酸化KdpE反过来打开的操纵子，编码的Kdp复合物的表达。
The Kdp ATPase is a P-type ATPase consisting of three large protein subunits in a complex that probably contains 2 copies of each subunit. A small hydrophobic peptide, encoded in the same operon as the large subunits, may also participate. Kdp has very high affinity for K+ and serves to scavenge this ion when its concentration is low. Kdp responds to turgor pressure at two levels, at the level of activity and of expression. Kdp mediates net uptake when turgor is low, but mediates exchange without net change when turgor is normal. Kdp is expressed only when turgor is low. This control is mediated by a pair of regulatory proteins, members of the class of 'sensor-effector' regulators widely distributed in bacteria. It is suggested that low turgor changes the conformation of the KdpD 'sensor' protein, activating its presumed kinase activity to phosphorylate KdpE, the 'effector' protein, and phospho-KdpE in turn turns on expression of the operon that encodes the Kdp complex.