CAJ | 학술논문

研究大肠杆菌单链结合蛋白(single-stranded DNA-binding protein,SSB)与单链DNA(singlestranded DNA,ssDNA)的相互作用对于了解其在DNA复制、重组和修复中的作用是非常重要的.通过表面等离子共振技术(surface plasmon resonance,SPR)得到了在有、无镁离子的情况下,SSB与ssDNA两者的平衡解离常数(equilibrium dissociation constant,KD)分别为9.67×10-7 M和4.79×10-7 M,阐明了镁离子对于两者作用形式的影响.利用原子力显微镜技术分别观察SSB蛋白、ssDNA和SSB-ssDNA复合物的成像,为下一步研究SSB在DNA代谢中作用模式的单分子可视化奠定了基础.
연구대장간균단련결합단백(single-stranded DNA-binding protein,SSB)여단련DNA(singlestranded DNA,ssDNA)적상호작용대우료해기재DNA복제、중조화수복중적작용시비상중요적.통과표면등리자공진기술(surface plasmon resonance,SPR)득도료재유、무미리자적정황하,SSB여ssDNA량자적평형해리상수(equilibrium dissociation constant,KD)분별위9.67×10-7 M화4.79×10-7 M,천명료미리자대우량자작용형식적영향.이용원자력현미경기술분별관찰SSB단백、ssDNA화SSB-ssDNA복합물적성상,위하일보연구SSB재DNA대사중작용모식적단분자가시화전정료기출.
Study of interaction of E.coli single-stranded DNA-binding protein (SSB) with its substrate, single-stranded DNA (ssDNA), is very important for understanding its essential roles in replication, recombination and repair of DNA. In this report, interaction of SSB with ssDNA was monitored by surface plasmon resonance (SPR) and directly observed using atomic force microscopy (AFM), which presented an attempt to investigate the binding mode of SSB by a single-molecule visualization methodology. The resulting SSB protein was a correctly folded tetramer with an apparent binding to 43-met ssDNA with the equilibrium dissociation constant (KD) of 9.67×10-7 M and 4.79×10-7 M respectively whether MgCl2 was present or not as determined by SPR. In the AFM images, individual ssDNA, SSB protein and SSB-ssDNA complex were visualized. The used ssDNA was long enough for cooperative SSB binding and the authors observed that SSB protein distributed on ssDNA non-specifically.