Endosymbiotic

In contrast to common usage, the distinction between photosynthetic and respiratory Rieske proteins does not seem to make sense. The mitochondrial Rieske protein is closely related to that of photosynthetic purple bacteria, which represent the endosymbiotic ancestors of mitochondria (for a review, see also (99)). Moreover, during its evolution Rieske s protein appears to have existed prior to photosynthesis (100, 101), and the photosynthetic chain was probably built around a preexisting cytochrome be complex (99). The evolution of Rieske proteins from photosynthetic electron transport chains is therefore intricately intertwined with that of respiration, and a discussion of the photosynthetic representatives necessarily has to include excursions into nonphotosynthetic systems. 

Associations between endosymbiotic bacteria and the Homoptera, Blattaria, and Coleoptera are common. One of the best known is that between Biicli-nera and the aphids (149,150). Both partners are obligate and mutualistic symbionts, and the aphids cannot survive without the bacteria (150). Buclmera, in fact. 

V. Bianciotto, C. Bandi, D. Minerdi, M. Sironi, H. V. Tichy, and P. Bonfante, An obligately endosymbiotic fungus it.self harbors obligately intracellular bacteria. Applied Environ. Microbiol. 62 3005 (1996). 

Some of the strange bedfellows one finds in natural relationships presumably reflect a multiplicity of interactions. Lichens, for example, consist of fungal units and either algal or cyanobacteria in a symbiotic (possibly a master/slave) relationship. In endosymbiotic relationships, compound organisms are constituted by algae (e.g. the zoochlorella of green hydra, and... 

Hoerauf, A., Volkmann, L., Hamelmann, C., Adjei, O., Autenrieth, I.B., Fleischer, B. and Buttner, D.W. (2000a) Endosymbiotic bacteria in worms as targets for a novel chemotherapy in filariasis. Lancet 355, 1242-1243. 

Taylor, M.J., Cross, H.F. and Bilo, K. (2000) Inflammatory responses induced by the filarial nematode Brugia malayi are mediated by lipopolysaccharide-like activity from endosymbiotic Wolbachia bacteria. Journal of Experimental Medicine 191, 1429-1436. 

According to the endosymbiotic hypothesis, the eukaryotes used genes from both bacteria (alpha-protobacteria) and cyanobacteria. The first led to the development of mitochondria, the second to that of chloroplasts, i.e., cell organelles which are highly important for energy production (ATP synthesis) and photosynthesis. 

Patron NJ, Rogers MB, Keeling PJ (2006) Comparative rates of evolution in endosymbiotic... 

Many of the animals harbor endosymbiotic bacteria that are sulflde oxidizers, such as the giant tube worms Riftta pachyptila), which reach lengths of 1 m. As shown in Figure 19.19, the tube worms are essentially a closed sac, having no mouth, digestive system, or other means of processing particulate food. 

Endosymbiotic Of a close biological association in which an organism lives inside its host. 

Cholesterol is found almost exclusively in eukaryotic cells. Animal membranes contain substantially more cholesterol than plant membranes, in which cholesterol is usually replaced by other sterols. There is no cholesterol at all in prokaryotes (with a few exceptions). The inner mitochondrial membrane of eukaryotes is also low in cholesterol, while it is the only membrane that contains large amounts of cardiolipin. These facts both support the endosymbiotic theory of the development of mitochondria (see p. 210). 

The older, traditional model of global oxygen history arguably starts off with a paper (Cloud 1968) that appeared at the time when Margulis was reviving endosymbiotic theory. Further developed and supported by much evidence... 

The outcome of, or perhaps the support for, the endosymbiont transferring its genes to the nucleus was the evolution of new machinery in the eukaryotic cell to send the nuclear-encoded proteins back to the degenerate endosymbiont to allow the latter to function. Moreover, it is of note that the large majority of extant mitochondrial proteins are not of endosymbiotic or a-proteobacterial origin. These proteins have either been recruited... 

The insertion of (i-barrel precursors is one of the two translocation processes, besides the sorting of inner membrane and IMS proteins, that are clearly derived from a eubacterial translocation system. (1-Barrel proteins are exclusively found in the outer membranes of Gram-negative bacteria and of endosymbiotic organelles such as mitochondria and plastids (Wim-... 

Rotte C, Stejskal F, Zhu G, Keithly JS, Martin W (2001) Pyruvate NADP+ oxidoreductase from the mitochondrion of Euglena gracilis and from the apicomplexan Cryptosporidium parvum a biochemical relic linking pyruvate metabolism in mitochondriate and amitochondriate protists. Mol Biol Evol 18 710-720 Schnarrenberger C, Martin W (2002) Evolution of the enzymes of the citric acid cycle and the glyoxylate cycle of higher plants. A case study of endosymbiotic gene transfer. Eur J Biochem 269 868-883... 

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