Faculty and Research Interests
William T. McAllister, PhD
Professor and Chair
Science Center 2204
Department of Biochemistry, University of New Hampshire, NH
Figure 1. Model of an EC with a misaligned Base Comparison of the structure of the T7 RNAP EC observed in the open configuration in the presence of the correct incoming NTP (left) and a model of a misaligned EC in which the TSn base is rotated out of the preinsertion site, allowing the TSn+1 base to pair with the incoming substrate (right). The protein is shown as a transparent surface; DNA template strand (TS) is red, RNA primer yellow, incoming NTP blue, TSn base white, TSn+1 base light red, and Y and Z helices (residues 624 to 658) and side chains of residues implicated in fidelity (Y639, G640, F644, G645, and H784) are in pink (See Pomerantz et al, Mol. Cell, 2006).
Work in our group is focused upon the structure and function of single subunit DNA-dependent RNA polymerases that are encoded by bacteriophage T7 and its relatives. Due to their structural simplicity and ease of genetic and biochemical manipulation these enzymes have proven extremely useful in elucidating fundamental aspects of the transcription process. Moreover, these enzymes are members of the pol I family of polymerases that includes DNA polymerases and reverse transcriptases, providing further insights into general mechanisms of nucleotide polymerization, and how the members of this family have evolved to carry out related but differing processes. Importantly, the phage RNA polymerases are closely related to mitochondrial RNA polymerase, and our efforts have recently expanded to include these enzymes which are critical for eukaryotic cell function. Lastly, our interests include potential practical applications of these enzymes in expression systems in prokaryotic and eukaryotic cells, and their application in nanotechnology, such as the development of information-dependent molecular motors. Our efforts in this field have enjoyed over 35 years of continuous NIH support, as well as support from other entities.
Figure 2. Details of RNA product displacement. Electrostatic and steric interactions at the upstream edge of the RNA:DNA hybrid separate the RNA from the DNA template, directing the RNA towards a positively charged exit pore. (See Jiang et al, Mol Cell. 2004)
PUBLICATIONS (Updated 3/2013)
- Savkina M, Temiakov D, McAllister WT, Anikin M. Multiple functions of yeast mitochondrial transcription factor Mtf1p during initiation. J Biol Chem, 285(6): 3957-64, Feb 2010.
- Ma N, McAllister WT. In a head-on collision, two RNA polymerases approaching one another on the same DNA may pass by one another. J Mol Biol, 391(5): 808-12, Sep 2009.
- Markov DA, Savkina M, Anikin M, Del Campo M, Ecker K, Lambowitz AM, De Gnore JP, McAllister WT. Identification of proteins associated with the yeast mitochondrial RNA polymerase by tandem affinity purification. Yeast, 26(8): 423-40, Aug 2009.
- Bandwar RP, Ma N, Emanuel SA, Anikin M, Vassylyev DG, Patel SS, McAllister WT. The transition to an elongation complex by T7 RNA polymerase is a multistep process. J Biol Chem, 282(31): 22879-86, Aug 2007.
- Pomerantz RT, Temiakov D, Anikin M, Vassylev DG, McAllister WT. A mechanism of nucleotide misincorporation during transcription due to template strand misalignment. Mol Cell, 24(2): 245–255, Oct 2006.
- Kashkina E, Anikin M, Brückner F, Pomerantz RT, McAllister WT, Cramer P, Temiakov D. Template misalignment in multisubunit RNA polymerases and transcription fidelity. Mol Cell, 24(2): 257-256, Oct 2006.
- Zlatanova J, McAllister WT, Borukhov S, Leuba SH. Single-molecule approaches reveal the idiosyncrasies of RNA polymerases. Structure,14(6): 953-66, Jun 2006. Review
- Ma K, Temiakov D, Anikin M, McAllister WT. Probing conformational changes in T7 RNA polymerase during initiation and termination using engineered disulfide linkages. Proc Natl Acad Sci, 102(49): 17612-7, Dec 2005.
- Pomerantz RT, Ramjit R, Gueroui Z, Place C, Anikin M, Leuba S, Zlatanova J, McAllister WT. A tightly regulated molecular motor based upon T7 RNA polymerase. Nano Lett, 5(9): 1698-1703, Sep 2005.
- Jiang M, Ma N, Vassylyev DG, McAllister WT. RNA displacement and resolution of the transcription bubble during transcription by T7 RNA polymerase. Mol Cell, 15(5): 777-88, Sep 2004.
- Temiakov D, Patlan V, Anikin M, McAllister WT, Yokoyama S, Vassylyev DG. Structural basis for substrate selection by T7 RNA polymerase. Cell, 116(3): 381-391, Feb 2004. See commentary by R. Landick, Cell 116: 351-353.
- Temiakov D, Tahirov TH, Anikin M, McAllister WT, Vassylyev DG, Yokoyama S. Crystallization and preliminary crystallographic analysis of T7 RNA polymerase elongation complex. Acta Crystallogr D Biol Crystallogr, 59(Pt 1):185-7, Jan 2003.
- Kukarin A, Rong M, McAllister WT. Exposure of T7 RNA polymerase to the isolated binding region of the promoter allows transcription from a single-stranded template. J Biol Chem, 278(4):2419-24, Jan 2003.
- Temiakov D, Anikin M, McAllister WT. Characterization of T7 RNA polymerase transcription complexes assembled on nucleic acid scaffolds. J Biol Chem, 6; 277(49): 47035-43, Dec 2002.
- Ma K, Temiakov D, Jiang M, Anikin M, McAllister WT. Major conformational changes occur during the transition from an initiation complex to an elongation complex by T7 RNA polymerase. J Biol Chem, 277(45): 43206-15, Nov 2002.
- Temiakov D, Mentesana PE, Ma K, Mustaev A, Borukhov S, McAllister WT. The specificity loop of T7 RNA polymerase interacts first with the promoter and then with the elongating transcript, suggesting a mechanism for promoter clearance. Proc Natl Acad Sci U S A, 97(26):14109-14. Dec 2000.
- Rong M, He B, McAllister WT, Durbin RK. Promoter specificity determinants of T7 RNA polymerase. Proc Natl Acad Sci U S A, 95(2):515-9, Jan 1998.
- Raskin CA, Diaz GA, McAllister WT. T7 RNA polymerase mutants with altered promoter specificities. Proc Natl Acad Sci U S A, 90(8):3147-51, Apr 1993.
- Deuschle U, Pepperkok R, Wang FB, Giordano TJ, McAllister WT, Ansorge W, Bujard H. Regulated expression of foreign genes in mammalian cells under the control of coliphage T3 RNA polymerase and lac repressor. Proc Natl Acad Sci U S A, 86(14):5400-4, Jul 1989.
- Jolliffe LK, Carter AD, McAllister WT. Identification of a potential control region in bacteriophage T7 late promoters. Nature, 299(5884): 653-6, Oct 1982.