Characterization of cpeY and cpeZ mutants in Fremyella diplosiphon strain UTEX 481

<p>Phycoerythrin (PE) present on the outer phycobilisome (PBS) rods in <em>Fremyella diplosiphon</em> contains covalently attached phycoerythrobilin (PEB) chromophores for efficient photosynthetic light capture. Chromophore ligation on phycobiliprotein subunits occurs through bilin lyase catalyzed reactions. The <em>cpeY </em>and <em>cpeZ</em> genes in <em>F. diplosiphon</em> were shown to attach PEB on alph-82 of PE. To better understand the individual functions of <em>cpeY</em> and <em>cpeZ</em> in native cyanobacteria, we characterized PBS and PE purified from <em>cpeY</em> and <em>cpeZ</em> deletion mutants and compared them with wild type (WT). Both <em>cpeY</em> and <em>cpeZ </em>mutants generated much less PE than WT as well as assembling much less PE into the PBS. PE purified from <em>cpeY</em> mutant had phycocyanobilin on alpha-PE in place of PEB. The mutation of <em>cpeZ</em> affected the biosynthesis and accumulation of beta-PE with a red-shifted absorbance compared to WT PE. CpeY was shown to function as a bilin lyase, and CpeZ possibly functions as a chaperone.</p>

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biological Sciences

Year dc:date.available

2013

Author dc:creator

• Kronfel, Christina M

Contributors dc:contributor

• Schluchter, Wendy
• Liu, Zhengchang
• Clancy, Mary

• Phycobilisome, Phycobiliprotein, Phycocyanin, Phycoerythrin, Phycocyanobilin, Phycoerythrobilin
• Biochemistry
• Molecular Biology

Repository record dc:identifier

https://scholarworks.uno.edu/td/1642

OAI identifier oai:identifier

oai:scholarworks.uno.edu:td-2651