3c23
From Proteopedia
Structure of a bacterial DNA damage sensor protein with non-reactive Ligand
Structural highlights
Function[DISA_THEMA] Participates in a DNA-damage check-point. DisA forms globular foci that rapidly scan along the chromosomes searching for lesions (By similarity).[1] Has also diadenylate cyclase activity, catalyzing the condensation of 2 ATP molecules into cyclic di-AMP (c-di-AMP). c-di-AMP likely acts as a signaling molecule that may couple DNA integrity with a cellular process. Does not convert GTP to c-di-GMP.[2] 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 PubMedTo reveal mechanisms of DNA damage checkpoint initiation, we structurally and biochemically analyzed DisA, a protein that controls a Bacillus subtilis sporulation checkpoint in response to DNA double-strand breaks. We find that DisA forms a large octamer that consists of an array of an uncharacterized type of nucleotide-binding domain along with two DNA-binding regions related to the Holliday junction recognition protein RuvA. Remarkably, the nucleotide-binding domains possess diadenylate cyclase activity. The resulting cyclic diadenosine phosphate, c-di-AMP, is reminiscent but distinct from c-di-GMP, an emerging prokaryotic regulator of complex cellular processes. Diadenylate cyclase activity is unaffected by linear DNA or DNA ends but strongly suppressed by branched nucleic acids such as Holliday junctions. Our data indicate that DisA signals DNA structures that interfere with chromosome segregation via c-di-AMP. Identification of the diadenylate cyclase domain in other eubacterial and archaeal proteins implies a more general role for c-di-AMP in prokaryotes. Structural biochemistry of a bacterial checkpoint protein reveals diadenylate cyclase activity regulated by DNA recombination intermediates.,Witte G, Hartung S, Buttner K, Hopfner KP Mol Cell. 2008 Apr 25;30(2):167-78. PMID:18439896[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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