1334
Mutational analyses of I kappa B alpha and competition experiments with the synthetic peptides identified major phosphorylation sites by the bound kinase as Ser and Thr residues in the C-terminal acidic domain of I kappa B alpha .
 protein: phosphorylation sites; protein: I kappa B; protein: I kappa B; protein: C-terminal acidic domain; protein: I kappa B alpha; protein: kinase
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 protein: phosphorylation sites; protein: I kappa B; protein: I kappa B; protein: C-terminal acidic domain; protein: I kappa B alpha; protein: kinase