Biology:Diadenylate cyclase

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Short description: DNA binding protein

Diadenylate cyclase EC 2.7.7.85, DNA integrity scanning protein DisA is a DNA binding protein[1] participates in a DNA-damage check-point. DisA forms globular foci that rapidly scan along the chromosomes searching for lesions. Catalytic activity

2 ATP [math]\displaystyle{ \rightleftharpoons }[/math] 2 diphosphate + cyclic di-3',5'-adenylate.

This enzyme has 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. This rate-limiting step is the accessibility of the active site; mutating the possible exit tunnel (residues 128-130) increases product 2-fold despite Arg-130 being important for ATP-binding. Does not convert GTP to c-di-GMP.

References

  1. "Structural biochemistry of a bacterial checkpoint protein reveals diadenylate cyclase activity regulated by DNA recombination intermediates". Molecular Cell 30 (2): 167–78. April 2008. doi:10.1016/j.molcel.2008.02.020. PMID 18439896.