Two types of functionally distinct NAD(P)H dehydrogenases in Synechocystis sp strain PCC6803
Two types of functionally distinct NAD(P)H dehydrogenases in Synechocystis sp strain PCC6803
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DOI：
10.1074/jbc.m003706200
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发表时间：
2000-10-13
影响因子：
4.8
通讯作者：
Ogawa, T
中科院分区：
文献类型：
--
作者：
Ohkawa, H;Pakrasi, HB;Ogawa, T
ndhD基因编码NAD（P）H脱氢酶的膜蛋白组分。集胞藻PCC 6803基因组含有6个ndhD基因。通过成对破坏高度同源的ndhD基因构建了三个突变体。只有Delta ndhD 1/Delta ndhD 2（Delta ndhD 1/D2）突变体不能在光合异养条件下生长，并表现出低呼吸速率，尽管该突变体在空气中的光合自养条件下正常生长。Delta ndhD 3/Delta ndhD 4（Delta ndhD 3/D4）突变体在空气中生长非常缓慢，并且不吸收CO2。结果表明，在集胞藻PCC 6803细胞中存在两种功能不同的NAD（P）H酶。Δ ndhD 5/Δ ndhD 6（Δ ndhD 5/D 6）突变体像野生型菌株一样生长。在远红光（>710 nm）下，P700（+）在低强度下在Delta ndhD 1/D2和M55（ndhB-less突变体）中的水平较高。通过加入KCN后黑暗中荧光增加测量，质体醌库还原Q（A）（紧密结合的质体醌）的能力在Delta ndhD 1/D2和M55中远低于Delta ndhD 3/D4和Delta ndhD 5/D 6。我们的结论是，电子从NADPH转移到质体醌池主要由NdhD 1。NdhD 2型NAD（P）H酶。
The ndhD gene encodes a membrane protein component of NAD(P)H dehydrogenase. The genome of Synechocystis sp. PCC6803 contains 6 ndhD genes. Three mutants were constructed by disrupting highly homologous ndhD genes in pairs. Only the Delta ndhD1/Delta ndhD2 (Delta ndhD1/D2) mutant was unable to grow under photoheterotrophic conditions and exhibited low respiration rate, although the mutant grew normally under photoautotrophic conditions in air. The Delta ndhD3/Delta ndhD4 (Delta ndhD3/D4) mutant grew very slowly in air and did not take up CO2. The results demonstrated the presence of two types of functionally distinct NAD(P)H dehydrogenases in Synechocystis PCC6803 cells. The Delta ndhD5/Delta ndhD6 (Delta ndhD5/D6) mutant grew like the wild-type strain. Under far-red light (>710 nm), the level of P700(+) was high in Delta ndhD1/D2 and M55 (ndhB-less mutant) at low intensities. The capacity of Q(A) (tightly bound plastoquinone) reduction by plastoquinone pool, as measured by the fluorescence increase in darkness upon addition of KCN, was much less in Delta ndhD1/D2 and M55 than in Delta ndhD3/D4 and Delta ndhD5/D6. We conclude that electrons from NADPH are transferred to the plastoquinone pool mainly by the NdhD1 . NdhD2 type of NAD(P)H dehydrogenases.