Homologous gene conversion

Besides unequal crossover and transposition, a third mechanism can effect rapid changes in the genetic material. Similar sequences on homologous or nonhomol-ogous chromosomes may occasionally pair up and eliminate any mismatched sequences between them. This may lead to the accidental fixation of one variant or another throughout a family of repeated sequences and thereby homogenize the sequences of the members of repetitive DNA families. This latter process is referred to as gene conversion. 

Expansion could also occur by gene conversion during homologous recombination (Chapter 27, Section D)401 426 oj. during DNA repair.421425 Repeat sequences may also prevent proper formation of nucleosomes.4 ... 

Lichten, M Boris, R. H., and Haber, J. E. (1987). Meiotic gene conversion between dispersed homologous sequences occurs frequently in Saccharomyces cerevisiae. Genetics 115, 233-246. 

Paffett KS, Clikeman JA, Palmer S et al (2005) Overexpression of Rad51 inhibits double-strand break-induced homologous recombination but does not affect gene conversion tract lengths. DNA Repair (Amst) 4 687-698... 

Glycolysis provides the main source of ATP in Trypanosoma brucei, E histolytica, and G lamblia, which possess pyruvate kinase as well as a pyruvate phosphate dikinase for converting phosphoenolpyruvate (PEP) to pyruvate and generating ATP. Pyruvate phosphate dikinase is not a homolog of pyruvate kinase but is closely related to PEP synthase from bacteria. The enzyme catalyzes conversion of PEP to pyruvate accompanied by the synthesis of ATP from AMP and pyrophosphate. Genes encoding the enzyme have been isolated from E histolytica and G lamblia and have demonstrated considerable structural divergences. No specific inhibitor of this enzyme has yet been identified. 

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