Protein structure and function Essay Example | Topics and Well Written Essays - 250 words

Protein structure and function - Essay Example nce is responsible for the activities of the different subunits, for example, the exonuclease and excision activities in DNA polymerase I of prokaryotes (Gilbert 2000). The alpha helices in DNA polymerase organize themselves in the form of coiled coils, which are bundles of alpha helices that form superhelices. Hydrogen bonds and Van der Waal forces of attraction play a significant role in the tertiary structure of DNA polymerase. This gives a 3-D appearance of a clamp. For example in Gram-negative bacteria such as E. coli, DNA polymerases sustain nearness with nucleic acid templates by means of contact with sliding clamps, which enclose DNA thus connecting the polymerase and the substrate of the DNA (Argiriadi et al. 2006). DNA polymerase has several non-identical subunits depending on the type of organism in question. In eukaryotes, there are five different subunits namely alpha, beta, gamma, delta, and epsilon (Gilbert 2000). These subunits interact in the process of DNA replication with each subunit playing a distinct role. DNA polymerase also has several domains such as the zinc finger domain and the DNA binding domains. The zinc fingers comprise of interactions between sulphide, nitrogen and oxygen atoms of the neighbouring peptides with a zinc ion. These regions influence the function of DNA polymerase by enabling the binding of the enzyme to the template strand of DNA at the replication fork before the process of replication can commence (Styrer et al. 2002). Argiriadi, M. A., Goedken, E. R., Bruck, I., ODonnell, M., & Kuriyan, J 2006, â€Å"Crystal structure of a DNA polymerase sliding clamp from a Gram-positive bacterium,† BMC Structural Biology, vol.6 no. 2, pp.