The complete nucleotide sequence of the 23S RNA gene from the rrnB operon of Escherichia coli has been determined. The sequences of both strands of the entire gene were determined, most of the sequence was independently confirmed by use of alternate restriction fragments, and all restriction cuts overlapped. The DNA region corresponding to mature 23S rRNA contains 2904 nucleotides. Kethoxal-reactive sites protected by 30S subunits are found between positions 2300 and 28000, placing the subunit interface in this region of the molecule. The functional importance of this region is further supported by studies by other investigators, including homology with chloroplast and mitochondrial rRNA VSports手机版. .