2dla
From Proteopedia
Primase large subunit amino terminal domain from Pyrococcus horikoshii
Structural highlights
FunctionPRIL_PYRHO Regulatory subunit of DNA primase, an RNA polymerase that catalyzes the synthesis of short RNA molecules used as primers for DNA polymerase during DNA replication. Stabilizes and modulates the activity of the small subunit, increasing the rate of DNA synthesis, and conferring RNA synthesis capability. The DNA polymerase activity may enable DNA primase to also catalyze primer extension after primer synthesis. May also play a role in DNA repair.[HAMAP-Rule:MF_00701] Publication Abstract from PubMedArchaeal/eukaryotic primases form a heterodimer consisting of a small catalytic subunit (PriS) and a large subunit (PriL). The heterodimer complex synthesizes primer oligoribonucleotides that are required for chromosomal replication. Here, we describe crystallographic and biochemical studies of the N-terminal domain (NTD) of PriL (PriL(NTD); residues 1-222) that bind to PriS from a hyperthermophilic archaeon, Pyrococcus horikoshii, at 2.9 A resolution. The PriL(NTD) structure consists of two subdomains, the helix-bundle and twisted-strand domains. The latter is structurally flexible, and is expected to contain a PriS interaction site. Pull-down and surface plasmon resonance analyses of structure-based deletion and alanine scanning mutants showed that the conserved hydrophobic Tyr155-Tyr156-Ile157 region near the flexible region is the PriS-binding site, as the Y155A/Y156A/I157A mutation markedly reduces PriS binding, by 1000-fold. These findings and a structural comparison with a previously reported PriL(NTD)-PriS complex suggest that the presented alternative conformations of the twisted-strand domain facilitate the heterodimer assembly. Molecular basis for the subunit assembly of the primase from an archaeon Pyrococcus horikoshii.,Ito N, Matsui I, Matsui E FEBS J. 2007 Mar;274(5):1340-51. Epub 2007 Feb 5. PMID:17286576[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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