Question: which molecule initiates the halt of the cycle when damaged dna is detected in g1
[{'answer': 'Cdc25A', 'provenance': [{'wikipedia_id': '3730562', 'title': 'Cell cycle checkpoint', 'start_paragraph_id': 12, 'start_character': 522, 'end_paragraph_id': 12, 'end_character': 528, 'bleu_score': 1.0, 'section': 'Section::::G (restriction) checkpoint.\n'}]}, {'provenance': [{'wikipedia_id': '3730562', 'title': 'Cell cycle checkpoint', 'start_paragraph_id': 13, 'start_character': 0, 'end_paragraph_id': 13, 'end_character': 821, 'bleu_score': 0.508726035472102, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 691239451011438518}, 'section': 'Section::::G (restriction) checkpoint.\n'}]}]