Koerner T J, Meyer R R
J Biol Chem. 1983 Mar 10;258(5):3126-33.
We have isolated and purified to homogeneity a novel single-stranded DNA-binding protein from the Novikoff hepatoma. This protein is distinguished from other eukaryotic DNA-binding proteins by binding weakly, but cooperatively, to single-stranded DNA, by its ability to partially destabilize a double helix at 37 degrees C, and by its ability to stimulate DNA polymerase beta. The protein exists as a globular monomer of Mr = 48,000 and is capable of binding 45-49 nucleotides. It does not form a complex with the polymerase, but binds the DNA template, allowing an increased rate and extent of DNA synthesis. The enhancement of synthesis is greatest with larger gap-sized templates and with low polymerase concentrations. The mechanism of stimulation is thought to be due largely to placing the template strand into a conformation that facilitates rapid polymerization rather than strand displacement in advance of the polymerase. This protein has been named SSB-48.
我们从诺维科夫肝癌中分离并纯化出一种新型单链DNA结合蛋白，达到了均一性。这种蛋白与其他真核生物DNA结合蛋白不同，它与单链DNA的结合较弱但具有协同性，能在37℃时使双螺旋部分解链，还能刺激DNA聚合酶β。该蛋白以Mr = 48,000的球状单体形式存在，能够结合45 - 49个核苷酸。它不与聚合酶形成复合物，但能结合DNA模板，从而提高DNA合成的速率和程度。对于较大缺口大小的模板和低聚合酶浓度，合成增强最为显著。刺激机制被认为主要是由于将模板链置于一种便于快速聚合的构象中，而不是在聚合酶之前进行链置换。这种蛋白被命名为SSB - 48。
