3H4R

Crystal structure of E. coli RecE exonuclease

Summary for 3H4R

• Entry DOI: 10.2210/pdb3h4r/pdb
• Descriptor: Exodeoxyribonuclease 8 (1 entity in total)
• Functional Keywords: exonuclease, recombination, hydrolase, nuclease
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 30403.25

Authors

Bell, C.E.,Zhang, J. (deposition date: 2009-04-20, release date: 2009-05-26, Last modification date: 2024-02-21)

Primary citation

Zhang, J.,Xing, X.,Herr, A.B.,Bell, C.E.
Crystal structure of E. coli RecE protein reveals a toroidal tetramer for processing double-stranded DNA breaks.
Structure, 17:690-702, 2009

PubMed Abstract: Escherichia coli RecE protein is part of the classical RecET recombination system that has recently been used in powerful new methods for genetic engineering. RecE binds to free double-stranded DNA (dsDNA) ends and processively digests the 5'-ended strand to form 5'-mononucleotides and a 3'-overhang that is a substrate for single strand annealing promoted by RecT. Here, we report the crystal structure of the C-terminal nuclease domain of RecE at 2.8 A resolution. RecE forms a toroidal tetramer with a central tapered channel that is wide enough to bind dsDNA at one end, but is partially plugged at the other end by the C-terminal segment of the protein. Four narrow tunnels, one within each subunit of the tetramer, lead from the central channel to the four active sites, which lie about 15 A from the channel. The structure, combined with mutational studies, suggests a mechanism in which dsDNA enters through the open end of the central channel, the 5'-ended strand passes through a tunnel to access one of the four active sites, and the 3'-ended strand passes through the plugged end of the channel at the back of the tetramer.

PubMed: 19446525
DOI: 10.1016/j.str.2009.03.008

Experimental method

X-RAY DIFFRACTION (2.8 Å)