Analysis of bacterial-type plastidial RNA binding protein required for chloroplast development

点击翻译按钮获取中文摘要

NUS1 protein is plastidial RNA binding protein essential for chloroplast biogenesis under low temperature. NUS1 is structurally similar to the bacterial protein NusB required for rRNA expression. NUS1 protein accumulated abundantly in the pre-emerged immature leaf whereas it disappeared in the mature leaf. NUS1 has a molecular weight of 30 kDa, and the BN-PAGE analyses showed that NUS1 was involved in the ~110kDa protein complex. Mobility gel shift assays indicated that NUS1 protein bound to 5' precursor region of chloroplast 16S rRNA. NUS1-deficient mutant showed severe leaf chlorosis at low temperature. In the chlorotic leaves of the mutant seedling, maturation of chloroplast rRNA was impaired and the chloroplast translation/transcription capacity was severely suppressed, suggesting that NUS1 has important roles in the regulation of chloroplast genetic system during early leaf development in rice.