DNA polymerase III of Gram-positive eubacteria is a zinc metalloprotein conserving an essential finger-like domain
Graduate School of Biomedical Sciences
Life Sciences | Medicine and Health Sciences
DNA polymerase III (pol III) of Gram-positive eubacteria is a catalytically bifunctional DNA polymerase:3'-5' exonuclease [Low, R. L., Rashbaum, S. A., and Cozzarelli, N. R. (1976) J. Biol.Chem. 251, 1311-1325]. The pol III protein conserves, between its exonuclease and dNTP binding sites, a 35-residue segment of primary structure with the potential to form a zinc finger-like structure [Berg, J. M. (1990) Ann. Rev. Biochem. 19, 405-421]. This paper describes results of experiments which probe the capacity of this segment to bind zinc and the role of this segment in enzyme function. The results of metal and mutational analysis of a model pol III derived from Bacillus subtilis indicate that (i) the Gram-positive pol III is a metalloprotein containing tightly bound zinc in a stoichiometry of 1, (ii) the zinc atom is bound within the 35-residue segment, likely in one of two probable finger-like structures, and (iii) the integrity of the zinc-bound structure is specifically critical to the formation and/or function of the enzyme's polymerase site.
DOI of Published Version
Biochemistry. 1998 Nov 3;37(44):15254-60. Link to article on publisher's site
Barnes MH, Leo C, Brown NC. (1998). DNA polymerase III of Gram-positive eubacteria is a zinc metalloprotein conserving an essential finger-like domain. GSBS Student Publications. https://doi.org/10.1021/bi981113m. Retrieved from https://escholarship.umassmed.edu/gsbs_sp/79