This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Structure and function of protein, Subject name: Biochemistry
[{'content': 'The common feature of Nuclear Localization Signals is \nSelect and explain. \nA. They are rich in acidic amino acid residues and are located at the C-terminus of the protein, B. They are rich in basic amino acid residues and are located at the C-terminus of the protein, C. They are rich in acidic amino acid residues and may be located anywhere in the protein sequence, D. They are rich in basic amino acid residues and may be located anywhere in the protein sequence', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Many nuclear proteins contain NLSs that are rich in basic arginine and lysine residues, which may be located anywhere in the polypeptide chain. Reference: Harper; 30th edition', 'role': 'assistant'}]