Extended structure of pleiotropic DNA repair-promoting protein PprA from Deinococcus radiodurans.
Adachi, M., Shimizu, R., Shibazaki, C., Satoh, K., Fujiwara, S., Arai, S., Narumi, I., Kuroki, R.(2019) FASEB J 33: 3647-3658
- PubMed: 30481062 
- DOI: https://doi.org/10.1096/fj.201801506R
- Primary Citation of Related Structures:  
6A27, 6A28, 6A29 - PubMed Abstract: 
Pleiotropic protein promoting DNA repair A (PprA) is a key protein facilitating the extreme radiation resistance of Deinococcus radiodurans. PprA is a unique protein to the genus Deinococcus and exists as an oligomer ranging from a tetramer to an ∼100-mer depending on protein concentrations. Here, the X-ray crystal structure of PprA was determined to clarify how PprA confers radiation resistance. The tertiary structure of dimeric PprA was elucidated by using mutants obtained with random and site-directed mutagenesis methods (W183R and A139R); these mutants have disabled DNA binding and polymerization functions. Because the mutant A139R and W183R proteins have dimeric assemblies with 2 different interfaces (Interfaces 1 and 2), the linear and oligomerized PprA model was constructed as a left-handed face-to-face periodic screw structure. In addition, the linear structure in solution was confirmed by small-angle scattering experiments. The site-directed mutational analysis identified essential basic amino acids for DNA binding. These analytical data support the hypothesis that a complex assembly of PprA molecules, which are extended and have a screw structure, surrounds and stretches the DNA strand, acting as a novel guide to colocalize the DNA strands for efficient DNA repairs.-Adachi, M., Shimizu, R., Shibazaki, C., Satoh, K., Fujiwara, S., Arai, S., Narumi, I., Kuroki, R. Extended structure of pleiotropic DNA repair-promoting protein PprA from Deinococcus radiodurans.
Organizational Affiliation: 
Tokai Quantum Beam Science Center, National Institutes for Quantum and Radiological Science and Technology, Tokai, Japan.