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Abstract：
Replication of the mitochondrial (mt) genome in filamentous fungi is under-studied, and knowledge is based mainly on data from yeasts and higher eukaryotes. In this study, the mitochondrial DNA polymerase γ (Mip1) of the entomopathogenic fungus Metarhizium brunneum is characterized and analyzed with disruption experiments and its in silico interactions with key proteins implicated in mt gene transcription, i.e., mt RNA polymerase Rpo41 and mt transcription factor Mtf1. Disruption of mip1 gene and its partial expression influences cell growth, morphology, germination and stress tolerance. A putative in silico model of Mip1-Rpo41-Mtf1, which is known to be needed for the initiation of replication, was proposed and helped to identify potential amino acid residues of Mip1 that interact with the Rpo41-Mtf1 complex. Moreover, the reduced expression of mip1 indicates that Mip1 is not required for efficient transcription but only for replication. Functional differences between the M. brunneum Mip1 and its counterparts from Saccharomyces cerevisiae and higher eukaryotes are discussed.
摘要：
线粒体（mt）基因组在丝状真菌中的复制研究不足，知识主要基于酵母和高等真核生物的数据。在这项研究中,通过破坏实验及其与mt基因转录中涉及的关键蛋白的计算机相互作用来表征和分析昆虫病原真菌metarhiziumbrunneum的线粒体DNA聚合酶γ（Mip1），即，mtRNA聚合酶Rpo41和mt转录因子Mtf1。mip1基因的破坏及其部分表达影响细胞生长，形态学,发芽和胁迫耐受性。Mip1-Rpo41-Mtf1的推测的计算机模拟模型，已知启动复制是必需的，提出并有助于鉴定与Rpo41-Mtf1复合物相互作用的Mip1的潜在氨基酸残基。此外，mip1的表达降低表明Mip1不是有效转录所必需的,而是仅复制所必需的。讨论了酿酒酵母和高等真核生物的M.Mip1与其对应物之间的功能差异。
