{'fraction_non_alphanumeric': 0.022172949002217297, 'fraction_numerical': 0.005543237250554324, 'mean_word_length': 5.314685314685315, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Initiation of transcription in yeast mitochondria: analysis of origins of replication and of genes coding for a messenger RNA and a transfer RNA.

The initiation of transcription of the yeast mitochondrial genes coding for subunit I of cytochrome c oxidase (COX1) and for tRNA1Thr has been examined. COX1 messenger RNA synthesis is initiated in a conserved nonanucleotide sequence (ATATAAGTA) which we have previously found immediately upstream of ribosomal RNA genes at positions at which RNA synthesis starts. The 5'-end of the precursor of tRNA1Thr is located in a variant nonanucleotide motif (TTATAAGTA), which may be characteristic for tRNA genes. Using a partially purified fraction of mtRNA polymerase, we demonstrate that RNA synthesis is precisely initiated in vitro in nonanucleotide sequences preceding both ribosomal RNA-, tRNA- and messenger RNA-encoding genes and origins of replication.