Crystal structure of an archaebacterial DNA polymerase

摘要: Abstract Background: Members of the Pol II family DNA polymerases are responsible for chromosomal replication in eukaryotes, and carry out highly processive when attached to ring-shaped processivity clamps. The sequences distinct from those members well-studied I polymerases. polymerase archaebacterium Desulfurococcus strain Tok (D. Pol) is a member that retains catalytic activity at elevated temperatures. Results: crystal structure D. has been determined 2.4 A resolution. architecture this type resembles bacteriophage RB69, with which it shares less than ∼20% sequence identity. As central region located within ‘palm' subdomain strikingly similar corresponding regions structural scaffold surrounds core unrelated 3′–5′ proofreading exonuclease domain domains RB69 same position relative as seen on opposite side palm compared its location N-terminal similarity RNA-binding domains. Sequence alignments suggest conserved eukaryotic δ ϵ. Conclusions: confirms modes binding template extrusion newly synthesized duplex likely be both However, mechanism by product transits quite different. discovery seems an module raises possibility interact RNA.