Colon cancer is a common malignant tumor in the digestive tract. Exploring new treatment targets is of great significance for improving the survival rate of colon cancer patients. The present study mainly analyzes the impact of proliferation essential genes (PLEGs) on the prognosis and chemotherapy response of colon cancer patients, as well as identifying the expression and cellular functions of important PLEG. The DepMap database was utilized for identification of PLEG in colon cancer cells. Through DEGs screening, WGCNA, univariate cox regression survival analysis, and LASSO, a PLEG signature (PLEGs) model was constructed. The impact of PLEGs on the prognosis of colon cancer patients and their response to chemotherapy was further analyzed. Finally, we conducted a random forest analysis and implemented functional experiments to investigate the prominent PLEG that is linked to the development of colon cancer. Based on the expression and prognosis of PLEG, we constructed a PLEGs prognosis model which can effectively predict the prognosis of colon cancer patients and their response to chemotherapy treatment. Random forest analysis showed that UBA1 is a key PLEG in the progression of colon cancer. Immunohistochemistry results revealed that UBA1 protein is significantly upregulated in colon cancer tissues. Cell functional experiments demonstrated that knocking down UBA1 can inhibit the proliferation, invasion, and migration abilities of colon cancer cells. PLEGs have the potential to serve as predictive biomarkers for prognosis and chemotherapy response in colon cancer patients. Among the PLEG, UBA1 plays a prominent role in promoting the malignant progression of colon cancer cells.