Small DNA deletions creating avirulence in Streptococcus pyogenes.
Small DNA deletions creating avirulence in Streptococcus pyogenes.
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DOI：
10.1126/science.6089334
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发表时间：
1984-08
期刊：
影响因子：
56.9
通讯作者：
J. Spanier;S. Jones;P. Cleary
中科院分区：
文献类型：
--
作者：
J. Spanier;S. Jones;P. Cleary
M蛋白是A组链球菌表面的抗原，使这些细菌能够抵抗吞噬作用。将编码M12蛋白的DNA克隆到大肠杆菌中，作为同位素标记的杂交探针，比较从M+和M-等基因培养物中分离的基因组DNA，以阐明这种变异的遗传基础。来自两个自发的、独立的M变异体的DNA包含小的(约50个碱基对)缺失，这些缺失被映射到M蛋白编码序列内或邻近的相同的限制性片段。结合这些缺失的多效性，这表明它们定义了一种监管开关。
The M protein is the antigen on the surface of group A streptococci that allows these bacteria to resist phagocytosis. DNA encoding the M12 protein was cloned into Escherichia coli and used as an isotopically labeled hybridization probe to compare genomic DNA's isolated from M+ and M- isogenic cultures in an effort to elucidate the genetic basis of this variation. DNA's from two spontaneous, independent M- variants contained small (approximately 50 base pairs) deletions which were mapped to identical restriction fragments within or adjacent to the M protein coding sequence. Taken together with the pleiotropic nature of these deletions, this suggests that they define a regulatory switch.