4d6o
From Proteopedia
THE CRYSTAL STRUCTURE OF I-DMOI IN COMPLEX WITH ITS TARGET DNA AT 1H INCUBATION IN 5MM MG (STATE 2)
Structural highlights
FunctionDMO1_DESMO Endonuclease involved in intron homing. Recognizes a recognizes up to 20 bp of DNA in the 23S rRNA gene intron. It has a slow turnover rate and cuts the coding strand with a slight preference over the non-coding strand. Publication Abstract from PubMedThe enzymatic hydrolysis of DNA phosphodiester bonds has been widely studied, but the chemical reaction has not yet been observed. Here we follow the generation of a DNA double-strand break (DSB) by the Desulfurococcus mobilis homing endonuclease I-DmoI, trapping sequential stages of a two-metal-ion cleavage mechanism. We captured intermediates of the different catalytic steps, and this allowed us to watch the reaction by 'freezing' multiple states. We observed the successive entry of two metals involved in the reaction and the arrival of a third cation in a central position of the active site. This third metal ion has a crucial role, triggering the consecutive hydrolysis of the targeted phosphodiester bonds in the DNA strands and leaving its position once the DSB is generated. The multiple structures show the orchestrated conformational changes in the protein residues, nucleotides and metals during catalysis. Visualizing phosphodiester-bond hydrolysis by an endonuclease.,Molina R, Stella S, Redondo P, Gomez H, Marcaida MJ, Orozco M, Prieto J, Montoya G Nat Struct Mol Biol. 2014 Dec 8. doi: 10.1038/nsmb.2932. PMID:25486305[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. Loading citation details.. Citations No citations found See AlsoReferences
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