Helicobacter pylori porCDAB and oorDABC genes encode distinct pyruvate:flavodoxin and 2-oxoglutarate:acceptor oxidoreductases which mediate electron transport to NADP
Helicobacter pylori porCDAB and oorDABC genes encode distinct pyruvate:flavodoxin and 2-oxoglutarate:acceptor oxidoreductases which mediate electron transport to NADP
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DOI：
10.1128/jb.180.5.1119-1128.1998
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发表时间：
1998-03-01
影响因子：
3.2
通讯作者：
Kelly, DJ
中科院分区：
文献类型：
--
作者：
Hughes, NJ;Clayton, CL;Kelly, DJ
幽门螺旋杆菌是一种既不含丙酮酸也不含2-氧戊二酸脱氢酶活性的微嗜气细菌，前人的研究（N， J, Hughes， P, a, Chalk， C， L. Clayton, and D， J, Kelly， J. Bacteriol, 175:3953-3959, 1995）表明乙酰辅酶a （acetyl- coa）和琥珀酰辅酶a的主要生成途径分别是丙酮酸：黄氧还毒素氧化还原酶（for）和2-氧戊二酸：受体氧化还原酶（OOR）。heterotetrameric蛋白纯化的几率,子单元的48 (PorA), 36 (PorB), 24(猪肉)、14 (PorD) kDa,在这项研究的可怜被净化,它同样是由多肽的43 (OorA), 33 (OorB), 24 (OorC)和10 (OorD) kDa,运动和整个都是氧气不稳定和可能的主要贡献者的微量需氧的表现型H,幽门,与穷,无法使用之前确认了的可怜flavodoxin (FldA)作为电子受体,虽然纯化的酶不能还原NAD(P)，但来自丙酮酸和2氧葡萄糖酸的电子都可以还原细胞提取物中的NADP，这与这些氧化还原酶作为呼吸电子供体提供NADPH的作用一致。对幽门螺杆菌per、por和fldA基因进行了克隆和测序，推断的por基因产物与古细菌4亚基2-氧酸受体氧化还原酶具有显著的序列相似性。OorA和-B的氨基酸序列与好氧嗜盐菌（halobium halobium）的两个亚基POR更接近。porD和oorD都编码完整的铁还原蛋白样亚基，POR和OOR可能是幽门螺杆菌中必需的酶，因为porB和oorA的插入失活似乎是致命的。
Helicobacter pylori, a major cause of human gastric disease, is a microaerophilic bacterium that contains neither pyruvate nor 2-oxoglutarate dehydrogenase activity, Previous studies (N, J, Hughes, P, A, Chalk, C, L. Clayton, and D, J, Kelly, J. Bacteriol, 177:3953-3959, 1995) have indicated that the major routes for the generation of acetyl coenzyme A (acetyl-CoA) and succinyl-CoA are via pyruvate:flavodoxin oxidoreductase (FOR) and 2-oxoglutarate:acceptor oxidoreductase (OOR), respectively, The purified POR is a heterotetrameric protein, with subunits of 48 (PorA), 36 (PorB), 24 (PorC), and 14 (PorD) kDa, In this study OOR has been purified, and it is similarly composed of polypeptides of 43 (OorA), 33 (OorB), 24 (OorC), and 10 (OorD) kDa, Both POR and OOR are oxygen labile and are likely to be major contributors to the microaerophilic phenotype of H, pylori, Unlike POR, OOR was unable to use a previously identified flavodoxin (FldA) as an electron acceptor, Although the purified enzymes were unable to reduce NAD(P), electrons from both pyruvate and 2 oxoglutarate could reduce NADP in cell extracts, consistent with a role for these oxidoreductases in the provision of NADPH as a respiratory electron donor, The H. pylori per, oor, and fldA genes were cloned and sequenced, The deduced por gene products showed significant sequence similarity to archaeal four-subunit 2-oxoacid:acceptor oxido-reductases, However, the amino acid sequences of OorA and -B mere more closely related to that of the two-subunit POR of the aerobic halophile Halobacterium halobium. Both porD and oorD encode integral ferredoxinlike subunits, POR and OOR are probably essential enzymes in H. pylori, as insertion inactivation of porB and oorA appeared to be lethal.