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Investigation Of The Amino Acids Responsible For Isomerase Activity Through Mutagenesis Of Bilin Lyase Mpew From Synechococcus Sp. A15-62, Kourtney Weaver
Investigation Of The Amino Acids Responsible For Isomerase Activity Through Mutagenesis Of Bilin Lyase Mpew From Synechococcus Sp. A15-62, Kourtney Weaver
Senior Honors Theses
Synechococcus sp. A15-62 is a marine cyanobacterium that undergoes Type IV chromatic acclimation (CA4) by altering the bilin content of the phycobilisome (PBS) or light harvesting complex to match the light color of its environment. The PBS is a protein complex comprised of rods containing phycobiliproteins (PBP) and linker proteins. In this species, phycoerythrin I and phycoerythrin II (PEI and PEII) are the phycobiliproteins located on the distal ends of the rods and the alpha () subunits of these proteins are the ones with altered bilin content during CA4. Bilin chromophores such as phycoerythrobilin (PEB) and phycourobilin (PUB) are bound …
Cpef Is The Bilin Lyase That Ligates The Doubly Linked Phycoerythrobilin On Phycoerythrin In The Cyanobacterium Fremyella Diplosiphon, Wendy M. Schluchter, R. B. Cole, D. M. Kehoe, M. N. Boutaghou, J. A. Karty, A. Gutu, L. S. Hernandez, J. P. Frick, C. V. Hernandez, C. M. Kronfel
Cpef Is The Bilin Lyase That Ligates The Doubly Linked Phycoerythrobilin On Phycoerythrin In The Cyanobacterium Fremyella Diplosiphon, Wendy M. Schluchter, R. B. Cole, D. M. Kehoe, M. N. Boutaghou, J. A. Karty, A. Gutu, L. S. Hernandez, J. P. Frick, C. V. Hernandez, C. M. Kronfel
Biological Sciences Faculty Publications
Phycoerythrin (PE) is a green light-absorbing protein present in the light-harvesting complex of cyanobacteria and red algae. The spectral characteristics of PE are due to its prosthetic groups, or phycoerythrobilins (PEBs), that are covalently attached to the protein chain by specific bilin lyases. Only two PE lyases have been identified and characterized so far, and the other bilin lyases are unknown. Here, using in silico analyses, markerless deletion, biochemical assays with purified and recombinant proteins, and site-directed mutagenesis, we examined the role of a putative lyase-encoding gene, cpeF, in the cyanobacterium Fremyella diplosiphon. Analyzing the phenotype of the cpeF deletion, …
The Roles Of The Chaperone-Like Protein Cpez And The Phycoerythrobilin Lyase Cpey In Phycoerythrin Biogenesis, Wendy M. Schluchter, D. M. Kehoe, J. A. Karty, T. Blensdorf, A. Gutu, J. P. Frick, A. Biswas, C. M. Kronfel
The Roles Of The Chaperone-Like Protein Cpez And The Phycoerythrobilin Lyase Cpey In Phycoerythrin Biogenesis, Wendy M. Schluchter, D. M. Kehoe, J. A. Karty, T. Blensdorf, A. Gutu, J. P. Frick, A. Biswas, C. M. Kronfel
Biological Sciences Faculty Publications
Phycoerythrin (PE) present in the distal ends of light-harvesting phycobilisome rods in Fremyella diplosiphon (Tolypothrix sp. PCC 7601) contains five phycoerythrobilin (PEB) chromophores attached to six cysteine residues for efficient green light capture for photosynthesis. Chromophore ligation on PE subunits occurs through bilin lyase catalyzed reactions, but the characterization of the roles of all bilin lyases for phycoerythrin is not yet complete. To gain a more complete understanding about the individual functions of CpeZ and CpeY in PE biogenesis in cyanobacteria, we examined PE and phycobilisomes purified from wild type F. diplosiphon, cpeZ and cpeY knockout mutants. We find that …
Interplay Between Differentially Expressed Enzymes Contributes To Light Color Acclimation In Marine Synechococcus, Wendy M. Schluchter, D. M. Kehoe, F. Partensky, J. A. Strnat, S. Pokhrel, J. A. A. Karty, L. Garczarek, A. A. Nguyen, J. E. Sanfilippo
Interplay Between Differentially Expressed Enzymes Contributes To Light Color Acclimation In Marine Synechococcus, Wendy M. Schluchter, D. M. Kehoe, F. Partensky, J. A. Strnat, S. Pokhrel, J. A. A. Karty, L. Garczarek, A. A. Nguyen, J. E. Sanfilippo
Biological Sciences Faculty Publications
Marine Synechococcus, a globally important group of cyanobacteria, thrives in various light niches in part due to its varied photosynthetic light-harvesting pigments. Many Synechococcus strains use a process known as chromatic acclimation to optimize the ratio of two chromophores, green-light-absorbing phycoerythrobilin (PEB) and blue-light-absorbing phycourobilin (PUB), within their light-harvesting complexes. A full mechanistic understanding of how Synechococcus cells tune their PEB to PUB ratio during chromatic acclimation has not yet been obtained. Here, we show that interplay between two enzymes named MpeY and MpeZ controls differential PEB and PUB covalent attachment to the same cysteine residue. MpeY attaches PEB to …