Crystal structure of the left-handed archaeal RadA helical filament: identification of a functional motif for controlling quaternary structures and enzymatic functions of RecA family proteins
Resource
Nucleic Acids Research 35 (6): 1787-1801
Journal
Nucleic Acids Research
Pages
1787-1801
Date Issued
2007
Date
2007
Author(s)
Chen, Li-Tzu
Ko, Tzu-Ping
Chang, Yuan-Chih
Lin, Kuei-An
Chang, Chia-Seng
Wang, Andrew H.-J.
Wang, Ting-Fang
Abstract
The RecA family of proteins mediates homologous recombination, an evolutionarily conserved pathway that maintains genomic stability by protecting against DNA double strand breaks. RecA proteins are thought to facilitate DNA strand exchange reactions as closed-rings or as right-handed helical filaments. Here, we report the crystal structure of a left-handed Sulfolobus solfataricus RadA helical filament. Each protomer in this left-handed filament is linked to its neighbour via interactions of a beta-strand polymerization motif with the neighbouring ATPase domain. Immediately following the polymerization motif, we identified an evolutionarily conserved hinge region (a subunit rotation motif) in which a 360 degrees clockwise axial rotation accompanies stepwise structural transitions from a closed ring to the AMP-PNP right-handed filament, then to an overwound right-handed filament and finally to the left-handed filament. Additional structural and functional analyses of wild-type and mutant proteins confirmed that the subunit rotation motif is crucial for enzymatic functions of RecA family proteins. These observations support the hypothesis that RecA family protein filaments may function as rotary motors.
SDGs
File(s)![Thumbnail Image]()
Loading...
Name
36.pdf
Size
1.69 MB
Format
Adobe PDF
Checksum
(MD5):75aa5c63519386c6ee4b78fcf33da937