Prokaryotic polymerases properties

DNA polymerases (Pol) have restricted properties so that the information encoded in DNA can be faithfully copied. The properties of prokaryotic polymerases (Komberg and Baker, 1992) can be summarized as ... 

Although many eukaryotic replication enzymes are generally similar to their prokaryotic counterparts, they do possess their own distinctive properties. For example, eukaryotes have five DNA polymerases designated a, j8, <5, , and y DNA polymerase a initiates the synthesis of both the leading and lagging strands. Further elongation of both strands is catalyzed by two DNA polymerase S complexes in the same manner as that of pol III in li. coli, that is, one complex synthesizes... 

Liu, J. and Doetsch, P.W. (1996) Template strand gap bypass is a general property of prokaryotic RNA polymerases implications for elongation mechanisms. Biochemistry, 35, 14999-15008. 

Enzymes - Eukaryotic cells contain five DNA polymerases. Three of them (polymerases oi, A, and s) are used during S phase replication. Table 24.2 and Table 24.3 describe the properties of eukaryotic and prokaryotic DNA polymerases. As in prokaryotes, the replication complex also contains other proteins, including helicases and a number of accessory proteins called replication factors. 

Other ansamycins are found in Nature, e.g. streptovaricin (from another Streptomyces) which acts in the same way as rifamycin but is not so selective amanitin (from the fungus Amanita phalloides) which is counter-selective, inhibiting eukaryotic but not prokaryotic DNA-dependent RNA polymerase and maytansine (from the bark of an African flowering plant) which has anti-cancer properties but is not established in the clinic. 

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