Bianco Piero R, Lyubchenko Yuri L
SUNY Microbiology and Immunology, Center for Single Molecule Biophysics, University at Buffalo, 321 Cary Hall, 3435 Main St, Buffalo, New York 14214.
Department of Microbiology and Immunology, University at Buffalo, Buffalo, New York.
Protein Sci. 2017 Apr;26(4):638-649. doi: 10.1002/pro.3114. Epub 2017 Mar 17.
In E. coli, the regression of stalled DNA replication forks is catalyzed by the DNA helicase RecG. One means of gaining access to the fork is by binding to the single strand binding protein or SSB. This interaction occurs via the wedge domain of RecG and the intrinsically disordered linker (IDL) of SSB, in a manner similar to that of SH3 domains binding to PXXP motif-containing ligands in eukaryotic cells. During loading, SSB remodels the wedge domain so that the helicase domains bind to the parental, duplex DNA, permitting the helicase to translocate using thermal energy. This translocation may be used to clear the fork of obstacles, prior to the initiation of fork regression.
在大肠杆菌中，停滞的DNA复制叉的回归由DNA解旋酶RecG催化。一种接近复制叉的方式是通过与单链结合蛋白（SSB）结合。这种相互作用通过RecG的楔形结构域和SSB的内在无序连接子（IDL）发生，其方式类似于真核细胞中SH3结构域与含PXXP基序的配体的结合。在加载过程中，SSB重塑楔形结构域，使解旋酶结构域与亲本双链DNA结合，从而允许解旋酶利用热能进行易位。在复制叉回归开始之前，这种易位可用于清除复制叉上的障碍物。
