PMID: 24666693
Mejia E, Burak M, Alonso A, Larraga V, Kunkel TA, Bebenek K, Garcia-Diaz M
Structures of the Leishmania infantum polymerase beta.
DNA Repair (Amst). 2014 Jun;18:1-9. doi: 10.1016/j.dnarep.2014.03.001. Epub 2014 , Mar 22.
Protozoans of the genus Leishmania, the pathogenic agent causing leishmaniasis, encode the family X DNA polymerase Li Pol beta. Here, we report the first crystal structures of Li Pol beta. Our pre- and post-catalytic structures show that the polymerase adopts the common family X DNA polymerase fold. However, in contrast to other family X DNA polymerases, the dNTP-induced conformational changes in Li Pol beta are much more subtle. Moreover, pre- and post-catalytic structures reveal that Li Pol beta interacts with the template strand through a nonconserved, variable region known as loop3. Li Pol beta Deltaloop3 mutants display a higher catalytic rate, catalytic efficiency and overall error rates with respect to WT Li Pol beta. These results further demonstrate the subtle structural variability that exists within this family of enzymes and provides insight into how this variability underlies the substantial functional differences among their members.