Characterization of Enzymes Involved in Bilin Attachment to Allophycocyanin in the Cyanobacterium Synechococcus sp. PCC 7002

The goal of this research is to identify and characterize enzymes involved in bilin attachment to the phycobiliprotein allophycocyanin in the cyanobacterium Synechococcus sp. PCC 7002. Candidates for lyases responsible for attachment of phycocyanobilin to allophycocyanin are two cpeS-like genes termed cpcS and cpcU, and one cpeT-like gene termed cpcT. In vitro bilin attachment reactions were conducted in the presence of the recombinant substrate apo-allophycocyanin (HT-ApcAB). Size exclusion HPLC showed that CpcS and HT-CpcU form a 1:1 heterodimeric complex and that HT-ApcAB is present as a monomer (áâ). Absorbance and fluorescence spectroscopy illustrated that both CpcS and HT-CpcU were required to get holo-allophycocyanin with phycocyanobilin attached to the cysteine-81 residue. Absorbance of the product at 615 nm was consistent with holo-monomeric allophycocyanin. Experiments were performed with HT-ApcD ApcB and HT-ApcF ApcA, but size exclusion HPLC showed they were in aggregated form.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biological Sciences

Year

2007

Author dc:creator

• Williams, Shervonda

Contributors dc:contributor

• Schluchter, Wendy
• Clancy, Mary
• Timpte, Candace

• Allophycocyanin
• Bilins
• Bilin lyase
• Cyanobacteria
• Phycobiliproteins
• Phycobiliprotein biosynthesis
• Phycocyanin
• Phycocyanobilin

Repository record dc:identifier

https://scholarworks.uno.edu/td/624

OAI identifier oai:identifier

oai:scholarworks.uno.edu:td-1624