Analysis of interaction between DNA and Deinococcus radiodurans PprA protein by atomic force microscopy.
A DNA repair-promoting protein, PprA, was isolated from a radiation resistant bacterium, Deinococcus radiodurans [I. Narumi, K. Sato, S. Cui, T. Funayama, S. Kitayama, H. Watanabe, PprA: a novel protein from Deinococcus radiodurans that stimulates DNA ligation, Mol. Microbiol. 54 (2004) 278-285]. Despite several studies, however, the function of PprA is not still clear. We used atomic force microscopy (AFM) to elucidate the role of this protein in the DNA repair pathway. In the present study, interaction between the linear DNA and PprA protein was imaged and analyzed by AFM without any fixation or staining. Though both end-bound and internally bound PprA was observed, the affinity of the end-bound protein was greater considering the proportion of features of binding analyzed by AFM. In some conditions, looping forms of the DNA-PprA complex were observed. Gel filtration high performance liquid chromatography (HPLC) was also conducted to estimate the molecular weight of this protein. The result of the HPLC analysis suggested that PprA formed multimers in buffer solution without DNA.
Murakami
Masahiro
M
Radiation Hazards Research Group, Research Center for Radiation Safety, National Institute of Radiological Sciences, 9-1, Anagawa-4-chome, Chiba-shi 263-8555, Japan. drhmmura@nirs.go.jp
Narumi
Issay
I
Satoh
Katsuya
K
Furukawa
Akira
A
Hayata
Isamu
I
D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D002851:Chromatography, High Pressure Liquid; D004260:DNA Repair; D004269:DNA, Bacterial / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D034301:Deinococcus / Q000378:metabolism*; D046911:Macromolecular Substances; D018625:Microscopy, Atomic Force; D008970:Molecular Weight; D011485:Protein Binding
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances