Kötter P, Entian K D
Johann Wolfgang Goethe-Universität Frankfurt, Institut für Mikrobiologie, Frankfurt, Germany.
Curr Genet. 1995 Jun;28(1):26-31. doi: 10.1007/BF00311878.
The Saccharomyces cerevisiae nuclear gene MRP-S9 was identified as part of the European effort in sequencing chromosome II. MRP-S9 encodes for a hydrophilic and basic protein of 278 amino acids with a molecular mass of 32 kDa. The C-terminal part (aa 153-278) of the MRP-S9 protein exhibits significant sequence similarity to members of the eubacterial and chloroplast S9 ribosomal-protein family. Cells disrupted in the chromosomal copy of MRP-S9 were unable to respire and displayed a characteristic phenotype of mutants with defects in mitochondrial protein synthesis as indicated by a loss of cytochrome c oxidase activity. Additionally, no activities of the gluconeogenetic enzymes, fructose-1,6-bisphosphatase and phosphoenolpyruvate carboxykinase, could be observed under conditions of glucose de-repression. The respiration-deficient phenotype could not be restored by transformation of the disruption strain with a wild-type copy of MRP-S9, indicating that MRP-S9 disruption led to rho- or rho0 cells. Sequence similarities of MRP-S9 to other members of the ribosomal S9-protein family and the phenotype of disrupted cells are consistent with an essential role of MRP-S9 is assembly and/or function of the 30s subunit of yeast mitochondrial ribosomes.
酿酒酵母核基因MRP - S9是欧洲对二号染色体测序工作的一部分。MRP - S9编码一种由278个氨基酸组成的亲水性碱性蛋白，分子量为32 kDa。MRP - S9蛋白的C末端部分（第153 - 278位氨基酸）与真细菌和叶绿体S9核糖体蛋白家族成员具有显著的序列相似性。MRP - S9染色体拷贝被破坏的细胞无法进行呼吸，并且表现出线粒体蛋白合成缺陷突变体的特征性表型，细胞色素c氧化酶活性丧失表明了这一点。此外，在葡萄糖去阻遏条件下，未观察到糖异生酶1,6 - 二磷酸果糖酶和磷酸烯醇式丙酮酸羧激酶的活性。用MRP - S9的野生型拷贝转化破坏菌株无法恢复呼吸缺陷表型，这表明MRP - S9的破坏导致了ρ - 或ρ0细胞。MRP - S9与核糖体S9蛋白家族其他成员的序列相似性以及破坏细胞的表型与MRP - S9在酵母线粒体核糖体30S亚基的组装和/或功能中起关键作用一致。
