REPEATING UNITS OF XENOPUS-LAEVIS OOCYTE-TYPE 5S DNA ARE HETEROGENEOUS IN LENGTH
REPEATING UNITS OF XENOPUS-LAEVIS OOCYTE-TYPE 5S DNA ARE HETEROGENEOUS IN LENGTH
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DOI：
10.1016/0092-8674(76)90198-7
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发表时间：
1976-01-01
期刊：
影响因子：
64.5
通讯作者：
BROWN, DD
中科院分区：
文献类型：
--
作者：
CARROLL, D;BROWN, DD
限制性内切酶Hind III和Hae III分别在1个和3个位点切割非洲爪蟾5S DNA，每个重复单位约为700个碱基对。通过限制性片段的变性作图，两种酶的切割位点均位于重复单元内。Hind III产物和1个Hae III片段的长度可变，表明5S DNA中重复单元长度的异质性。这种长度异质性仅限于主要的腺嘌呤+胸腺嘧啶[A + T]丰富的间隔区。重复单位彼此不同的离散量子约15个碱基对。富含A + T的间隔区主要由这种大小的串联亚重复序列组成。重复序列长度的异质性是由于主要重复单元的间隔区中这些亚重复序列的数量可变。
The restriction endonuclease enzymes Hind III and Hae III cleave Xenopus laevis 5S DNA at 1 and 3 sites, respectively, in each repeating unit of approximately 700 base pairs. The cleavage sites for both enzymes were located within the repeating unit by denaturation mapping of the restriction fragments. The Hind III products and 1 of the Hae III fragments are variable in length, indicating heterogeneity in the length of the repeating unit in 5S DNA. This length heterogeneity is confined to the major adenine + thymine [A + T] rich spacer region. Repeating units differ from each other by discrete quanta of approximtely 15 base pairs. The A + T rich spacer consisted largely of tandem subrepeats of just this size. The repeat-length heterogeneity is due to variable numbers of these subrepeats in the spacer regions of the major repeating units.