FIG 1.

Blue-light-regulated c-di-GMP PDE activity. (A) Domain architecture of the EAL-BLUF proteins and their derivatives used in this study. (B) Increase in the swim zone of the E. coli MG1655 yhjH strain expressing MBP-BldP1 and MBP-EB1 by light in semisolid agar supplemented with 0.1 mM IPTG. V, empty vector expressing MBP (pMal-c5x); 1, MBP-BldP1; 2, MBP-EB1. (C) Effect of the α-helical linker upstream of the EAL domains on light-dependent PDE activity. The EB1 and EB2 protein fragments were expressed from the pBAD vector in the MG1655 yhjH strain and spotted onto semisolid agar supplemented with 0.02% arabinose. V, empty vector (pBAD); 1, EB1 lacking the linker; 2, EB1 with the linker carrying the E712P mutation; 3, EB1 with the linker; 4, EB2 with the linker.