PriC 是革蘭氏陰性菌所特有的蛋白質，是複製重啟之引子合成體 (replication restart primosome) 組裝與產生活性時所必需要的一員，已知若此活性遭到壓制將對細 菌的生長造成極大影響。不同於 PriA 為首的組裝機制須靠多個相異的蛋白質協力聚 集，PriC 已知可獨力組裝以 PriC 為首的引子合成體，使停滯的 DNA 複製叉重新啟動。 在此研究，我們發現 PriC 可與另一引子合成體蛋白質 PriB 產生交互作用力；然令人好 奇的是，PriB 與 PriC 係屬於各自獨立的組裝途徑，不免產生許多新的疑問有待釐清。 在此兩年計劃，我們的初步成果顯示，PriC 與 PriB 之間有極強的交互作用，因此我們 想要進一步的研究其詳細的結合模式(第一年)、與其它引子合成體成員共協結合於 DNA 產生的影響以及抑制劑的篩選與開發(第二年)。本計劃所使用的革蘭氏陰性菌為 克雷伯氏肺炎桿菌(Klebsiella pneumoniae)；在台灣地區，嚴重的克雷伯氏菌抗藥性成 為台灣醫療中必須盡快解決的問題。因此我們希望除在學術上研究清楚 PriC 與 PriB 在 複製叉 DNA 上如何與其它引子合成體成員互動外，在臨床應用上亦希望能帶出數個有 潛力的抑制劑，以便提出可能能對抗克雷伯氏肺炎桿菌甚或其他抗藥性病原菌的醫療解答。 PriC protein, only found in the Gram-negative bacteria, is required for assembly of the replication restart primosome. Activities of the replication restart primosome are essential for cell growth and survival. In contrast to the PriA-directed primosome using multiprotein PriA/PriB/DnaT/DnaC complex for replication restart, PriC is able to do this on its own. In this study, we found the protein-protein interaction within PriC and PriB, raising a question as to how the interaction is involved in different assembly mechanisms. In this two-year project, we plan to study the PriB binding mode of PriC with DNA (first year), the role of the PriC-PriB complex in primosome assembly mechanisms in the presence of the other primosomal proteins (second year), and the inhibitor development (second year). The PriC and PriB used in this project are from Klebsiella pneumoniae. In Taiwan, many clinical strains of K. pneumoniae are highly resistant to antibiotics. Therefore, we hope that the resultant information can detail how PriC-PriB co-bind with other protein(s) at the forked DNA, and can bring some new and potential drugs targeting the antibiotic resistant K. pneumoniae and other pathogens.
