Zinc-bundle structure of the essential RNA polymerase subunit RPB10 from Methanobacterium thermoautotrophicum.Mackereth, C.D., Arrowsmith, C.H., Edwards, A.M., McIntosh, L.P.
(2000) Proc Natl Acad Sci U S A 97: 6316-6321
- PubMed: 10841539
- DOI: https://doi.org/10.1073/pnas.97.12.6316
- Primary Citation of Related Structures:
- PubMed Abstract:
The RNA polymerase subunit RPB10 displays a high level of conservation across archaea and eukarya and is required for cell viability in yeast. Structure determination of this RNA polymerase subunit from Methanobacterium thermoautotrophicum reveals a topology, which we term a zinc-bundle, consisting of three alpha-helices stabilized by a zinc ion. The metal ion is bound within an atypical CX(2)CX(n)CC sequence motif and serves to bridge an N-terminal loop with helix 3. This represents an example of two adjacent zinc-binding Cys residues within an alpha-helix conformation. Conserved surface features of RPB10 include discrete regions of neutral, acidic, and basic residues, the latter being located around the zinc-binding site. One or more of these regions may contribute to the role of this subunit as a scaffold protein within the polymerase holoenzyme.
Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.