2FCO

Crystal Structure of Bacillus stearothermophilus PrfA-Holliday Junction Resolvase

Summary for 2FCO

• Entry DOI: 10.2210/pdb2fco/pdb
• Descriptor: recombination protein U (penicillin-binding protein related factor A), MAGNESIUM ION, 1,2-ETHANEDIOL, ... (4 entities in total)
• Functional Keywords: flexibility, hydrolase
• Biological source: Geobacillus kaustophilus
• Total number of polymer chains: 2
• Total formula weight: 46317.13

Authors

Li, J.,Jedrzejas, M.J. (deposition date: 2005-12-12, release date: 2006-11-21, Last modification date: 2024-02-14)

Primary citation

Kelly, S.J.,Li, J.,Setlow, P.,Jedrzejas, M.J.
Structure, flexibility, and mechanism of the Bacillus stearothermophilus RecU Holliday junction resolvase.
Proteins, 68:961-971, 2007

PubMed Abstract: Here we report a high resolution structure of RecU-Holliday junction resolvase from Bacillus stearothermophilus. The functional unit of RecU is a homodimer that contains a "mushroom" like structure with a rigid cap and two highly flexible loops extending outwards. These loops appear to be highly flexible/dynamic, and presumably are directly involved in DNA binding and holding it for catalysis. Structural modifications of both the protein and DNA upon their interaction are essential for catalysis. An Mg2+ ion is present in each of the two active sites in this homodimeric enzyme, and two water molecules are coordinated with each Mg2+ ion. Our data are consistent with one of these water molecules acting as a nucleophile and the other as a general acid. The identities of the general base and general acid involved in catalysis and the Lewis acid that stabilizes the pentacovalent transition state phosphate ion are proposed. A model for the RecU-Holliday junction DNA complex is also proposed and discussed in the context of DNA binding and cleavage.

PubMed: 17557334
DOI: 10.1002/prot.21418

Experimental method

X-RAY DIFFRACTION (1.4 Å)