Structural and Spectroscopic Characterization of Modular Photoreceptors

Photoreceptors are signaling proteins that perceive a light signal and generate light-dependent biochemical responses. Cyanobacteriochromes (CBCRs) from photosynthetic cyanobacteria are an emerging family of bilin-based photoreceptors that are compact in size and diverse in absorption spectra. Their modularity and reversibility make them promising molecular switches in optogenetics and other biomedical applications. In this dissertation, I talk about how I applied crystallography, spectroscopy, and biochemical methods to investigate a few distinct CBCRs regarding the molecular mechanisms of spectral tuning, photoconversion, and light signaling. A major part of my thesis work focuses on a far-red sensing CBCR from Anabaena cylindrica. I present the crystal structures captured in different light-absorbing states, revealing mechanistic insights that challenge our current understanding of bilin-based photoreceptors. I also present my work in characterizing four spectroscopically distinct CBCRs from the same multi-sensor photoreceptor protein, both in isolated forms and in the full-length context. Based on spectral and structural studies, I discuss how bacterial signaling proteins combine different sensor domains in a single protein to achieve signal integration. Together, findings from these studies will provide mechanistic insights into how cyanobacteria sense light and other environmental cues in survival and adaptation, and present new strategies in protein engineering of optogenetic tools via synthetic biology.

Author dc:creator

• Linta Maruthurethu Biju (24399413)

• INTRODUCTION TO FAR-RED CYANOBACTERIOCHROMES
• ROOM-TEMPERATURE CRYSTALLOGRAPHY STUDIES ON ANACY_2551g3
• MULTI-SENSOR HISTIDINE KINASE ANACY_4718
• FOUR INDIVIDUAL GAF DOMAINS OF ANACY_4718
• HELIORHODOPSIN
• Biochemical and Structural Studies of a Novel Tetrameric Penicillin-Binding Protein from Bacillus cereus

Statement dc:rights

• In Copyright

DOI dc:identifier

https://doi.org/10.25417/uic.32993846.v1

OAI identifier oai:identifier

oai:figshare.com:article/32993846