2woe
From Proteopedia
Crystal Structure of the D97N variant of dinitrogenase reductase- activating glycohydrolase (DRAG) from Rhodospirillum rubrum in complex with ADP-ribose
Structural highlights
FunctionDRAG_RHORU Involved in the regulation of nitrogen fixation activity by the reversible ADP-ribosylation of one subunit of the homodimeric dinitrogenase reductase component of the nitrogenase enzyme complex. The ADP-ribosyltransferase (DraT) transfers the ADP-ribose group from NAD to dinitrogenase reductase. The ADP-ribose group is removed through the action of the ADP-ribosylglycohydrolase (DraG, this entry). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedADP-ribosylation is a ubiquitous regulatory posttranslational modification involved in numerous key processes such as DNA repair, transcription, cell differentiation, apoptosis, and the pathogenic mechanism of certain bacterial toxins. Despite the importance of this reversible process, very little is known about the structure and mechanism of the hydrolases that catalyze removal of the ADP-ribose moiety. In the phototrophic bacterium Rhodospirillum rubrum, dinitrogenase reductase-activating glycohydrolase (DraG), a dimanganese enzyme that reversibly associates with the cell membrane, is a key player in the regulation of nitrogenase activity. DraG has long served as a model protein for ADP-ribosylhydrolases. Here, we present the crystal structure of DraG in the holo and ADP-ribose bound forms. We also present the structure of a reaction intermediate analogue and propose a detailed catalytic mechanism for protein de-ADP-ribosylation involving ring opening of the substrate ribose. In addition, the particular manganese coordination in DraG suggests a rationale for the enzyme's preference for manganese over magnesium, although not requiring a redox active metal for the reaction. Mechanism of ADP-ribosylation removal revealed by the structure and ligand complexes of the dimanganese mono-ADP-ribosylhydrolase DraG.,Berthold CL, Wang H, Nordlund S, Hogbom M Proc Natl Acad Sci U S A. 2009 Aug 25;106(34):14247-52. Epub 2009 Aug 12. PMID:19706507[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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