Sandbox122: Difference between revisions
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==Interaction between FMN et LOV2 domain== | ==Interaction between FMN et LOV2 domain== | ||
The <scene name='Sandbox122/Fmn_ligand/1'>FMN</scene> (Flavin MonoNucleotide) is the ligand which is responsible for the light absorption. A single molecule of FMN is bound non convalently in the interior of LOV2 domain. FMN is stabilized thanks to hydrogen bonds, Van der Waals and electrostatic interactions. For example, atoms <scene name='Sandbox122/Arg_983/1'>R983</scene> and <scene name='Sandbox122/Arg_963/1'>R967</scene>(alpha C helix) create ionic bond with phosphate group of FMN. <scene name='Sandbox122/Q970/1'>Q970</scene>, N965, N998, N1008(alpha A helix and beta-strand C, D and E) aminoacid make some electrostatic interaction which stabilize FMN. Some results indicate that the majority of the FMN in the LOV2 domain exist in the protonated form. Researcher propose a reaction mechanism that involves excited-state proton transfer, on the nanosecond time scale , from the sulfhydryl group of the conserved cysteine to the N5 atom of FMN. | The <scene name='Sandbox122/Fmn_ligand/1'>FMN</scene> (Flavin MonoNucleotide) is the ligand which is responsible for the light absorption. A single molecule of FMN is bound non convalently in the interior of LOV2 domain. FMN is stabilized thanks to hydrogen bonds, Van der Waals and electrostatic interactions. For example, atoms <scene name='Sandbox122/Arg_983/1'>R983</scene> and <scene name='Sandbox122/Arg_963/1'>R967</scene>(alpha C helix) create ionic bond with phosphate group of FMN. <scene name='Sandbox122/Q970/1'>Q970</scene>,<scene name='Sandbox122/N965/1'>N965</scene> , N998, N1008(alpha A helix and beta-strand C, D and E) aminoacid make some electrostatic interaction which stabilize FMN. Some results indicate that the majority of the FMN in the LOV2 domain exist in the protonated form. Researcher propose a reaction mechanism that involves excited-state proton transfer, on the nanosecond time scale , from the sulfhydryl group of the conserved cysteine to the N5 atom of FMN. | ||
Blue light arrives on the only LOV2 cysteine residue(situate 4.2A from atom C(4a)) and induces formation of covalent cysteinyl-C(4a)adduct. (To explain that, refer to the scheme). This complex may interact directly with the kinase and regulate is activity. | Blue light arrives on the only LOV2 cysteine residue(situate 4.2A from atom C(4a)) and induces formation of covalent cysteinyl-C(4a)adduct. (To explain that, refer to the scheme). This complex may interact directly with the kinase and regulate is activity. | ||
Kinase will permit the autophosphorylation of phototropin. The rate of phosphorylatide phototropin acts to differential lateral gradients of auxin which is responsible of phototropism phenomenon. | Kinase will permit the autophosphorylation of phototropin. The rate of phosphorylatide phototropin acts to differential lateral gradients of auxin which is responsible of phototropism phenomenon. | ||
[[Image:1g28.jpg | thumb]] | [[Image:1g28.jpg | thumb]] | ||
[[Image:1G28.pdb_b.jpg | thumb]] | [[Image:1G28.pdb_b.jpg | thumb]] | ||
