4RNI:
reference: Formation and dimerization of the phosphodiesterase active site of the Pseudomonas aeruginosa MorA, a bi-functional c-di-GMP regulator., Phippen CW, Mikolajek H, Schlaefli HG, Keevil CW, Webb JS, Tews I, FEBS Lett. 2014 Dec 20;588(24):4631-6. doi: 10.1016/j.febslet.2014.11.002. Epub, 2014 Nov 11. PMID: 25447517

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