Danner D B, Smith H O, Narang S A
Proc Natl Acad Sci U S A. 1982 Apr;79(7):2393-7. doi: 10.1073/pnas.79.7.2393.
Competent Haemophilus cells recognize and preferentially take up Haemophilus DNA during genetic transformation. This preferential uptake is correlated with the presence on incoming DNA of an 11-base-pair (bp) sequence, 5'-A-A-G-T-G-C-G-G-T-C-A-3'. To prove that this sequence is the recognition site that identifies Haemophilus DNA to the competent cell, we have now constructed a series of plasmids, each of which contains the 11-bp sequence. Using two different assay systems we have tested the ability of fragments from these plasmids to compete with cloned Haemophilus DNA fragments that naturally contain the 11-bp sequence. We find that the addition of the 11-bp sequence to a DNA fragment is necessary and sufficient for preferential uptake of that fragment. However, plasmid DNAs containing this sequence may vary as much as 48-fold in uptake activity, and this variation correlates with the A+T-richness of the DNA flanking the 11-mer.
感受态嗜血杆菌细胞在遗传转化过程中能够识别并优先摄取嗜血杆菌DNA。这种优先摄取与进入的DNA上存在的一个11个碱基对（bp）的序列5'-A-A-G-T-G-C-G-G-T-C-A-3'相关。为了证明该序列是向感受态细胞识别嗜血杆菌DNA的识别位点，我们现在构建了一系列质粒，每个质粒都包含这个11 bp的序列。使用两种不同的检测系统，我们测试了这些质粒片段与天然含有11 bp序列的克隆嗜血杆菌DNA片段竞争的能力。我们发现，向DNA片段中添加11 bp序列对于该片段的优先摄取是必要且充分的。然而，含有该序列的质粒DNA在摄取活性上可能相差多达48倍，这种差异与11聚体侧翼DNA的A+T丰富度相关。
