枯草芽孢杆菌染色体末端停滞复制叉处DNA链的序列限制

Williams N K, Wake R G

Department of Biochemistry, University of Sydney, NSW, Australia.

Nucleic Acids Res. 1989 Dec 11;17(23):9947-56. doi: 10.1093/nar/17.23.9947.

The DNA sequence limits of the leading and lagging strands in the arrested clockwise replication fork at the terminus of the Bacillus subtilis chromosome have been investigated. On the basis of hybridization to synthetic oligonucleotides corresponding to known positions in the terminus region sequence it has been shown that neither the leading nor lagging strands, as they approach terC, traverse the distal inverted repeat, IRI. But a small fraction of the leading strands pass through the proximal inverted repeat, IRII. This is consistent with IRI being the functional inverted repeat in arresting the clockwise fork. But most of the forks appear to stop at least 100 nucleotides short of IRI, and at various positions extending over a distance of at least 100 nucleotides.

对枯草芽孢杆菌染色体末端停滞的顺时针复制叉中前导链和后随链的DNA序列界限进行了研究。基于与对应于末端区域序列中已知位置的合成寡核苷酸杂交，结果表明，前导链和后随链在接近terC时，均未穿过远端反向重复序列IRI。但是一小部分前导链穿过了近端反向重复序列IRII。这与IRI作为停滞顺时针复制叉的功能性反向重复序列是一致的。但是大多数复制叉似乎在距离IRI至少100个核苷酸处停止，并且在至少延伸100个核苷酸的不同位置处停止。