Strukturní dynamika transkripčního faktoru EL222 citlivého na světlo

Chaudhari, Aditya

(EN) Absorption of blue light by proteins featuring the light-oxygen-voltage (LOV) domain triggers physiological responses. One of the LOV-containing proteins, the bacterial transcription factor EL222, is used here as a model system to study the structural and dynamical changes induced by light. EL222 regulates gene expression in a light-dependent manner and has been used in optogenetic applications. EL222 consists of two domains: a light-sensitive LOV domain and a helix-turn-helix DNA-binding domain. In the absence of light, these domains are closely packed, inhibiting DNA binding. However, when exposed to light, the flavin mononucleotide (FMN) cofactor, initially non-covalently attached, forms a covalent bond with a nearby cysteine residue, triggering conformational changes that enable DNA binding. The objective of this study is to uncover the unknown molecular mechanism governing the transition between the dark and illuminated states. We utilized a combination of time-resolved spectroscopy techniques, advanced kinetic analysis methods, and incorporation of non-canonical amino acids (ncAA) as infrared probes of the microenvironment to understand the dynamics of FMN upon light illumination and the consequent structural changes. The intrinsic electronic and vibrational changes of FMN in aqueous...

guest :: login Digital Repository
		Search		Submit		Help		About