Variability of photosynthesis genes in purple bacteria and molecular determinants of their spectral properties

The structural genes of the photosynthetic apparatus of two purple bacteria, Amoebobacter (Amb.) purpureus ML1 and Roseospirillum (Rss.) parvum 930I, were investigated by molecular biological methods. Analyses were focused on their light harvesting (LH) 1 core antenna, which is encoded within the puf operon. The puf-operon of the purple sulfur bacterium Amb. purpureus differs from the puf operon of the purple non-sulfur bacteria by exhibiting multiple copies of the LH1 genes pufBA and by variations in gene transcription and expression. Horizontal transfer of genes between Amb. purpureus and Allochromatium vinosum might have played a role during the evolution of the multiple pufA genes. Along with extraordinary absorption properties of the LH1-antenna (909 nm), Rss. parvum exhibits substitutions of amino acids within the LH1 alpha and beta polypeptides at positions that are highly conserved in other purple bacteria. 3D structural models of the polypeptides suggest that cysteine side chains in particular are involved in the modulation of the spectral properties of Rss. parvum.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Oldenburg

Year

2003

Author dc:creator

• Tuschak, Christian

• [Keine Schlagwörter von Autor/in vergeben.]

Repository record source_url

http://oops.uni-oldenburg.de/202

OAI identifier oai:identifier

oai:oops.uni-oldenburg.de:202