5f4h
From Proteopedia
Archael RuvB-like Holiday junction helicase
Structural highlights
FunctionPINA_SULIR Promotes Holliday junction (HJ) branch migration and unwinds Y-shaped DNA (but not replication forks or dsDNA) in an ATP hydrolysis-dependent manner (PubMed:28238763). Stimulates cleavage by HJ resolvase Hjc (PubMed:28238763). Unwinds Y-shaped and 3'-flap DNA substrates. In the absence of other proteins stabilizes replication forks (prevents spontaneous unwinding); Hjc, Hjm (Hel308) and PINA coordinate HJ migration and cleavage of replication forks in a coordinated way (PubMed:29846688). Inhibits the 5'-3' (but not 3'-5') helicase activity of helicase Hjm (Hel308) on overhang DNA (PubMed:29846688). Probably acts as an ATP-dependent pump that pulls DNA through the hexamer (By similarity).[UniProtKB:Q5M2B1][1] [2] Publication Abstract from PubMedHolliday junction (HJ) is a hallmark intermediate in DNA recombination and must be processed by dissolution (for double HJ) or resolution to ensure genome stability. Although HJ resolvases have been identified in all domains of life, there is a long-standing effort to search in prokaryotes and eukarya for proteins promoting HJ migration. Here, we report the structural and functional characterization of a novel ATPase, Sulfolobus islandicusPilT N-terminal-domain-containing ATPase (SisPINA), encoded by the gene adjacent to the resolvase Hjc coding gene. PINA is conserved in archaea and vital for S. islandicus viability. Purified SisPINA forms hexameric rings in the crystalline state and in solution, similar to the HJ migration helicase RuvB in Gram-negative bacteria. Structural analysis suggests that ATP binding and hydrolysis cause conformational changes in SisPINA to drive branch migration. Further studies reveal that SisPINA interacts with SisHjc and coordinates HJ migration and cleavage. Structure and Function of a Novel ATPase that Interacts with Holliday Junction Resolvase Hjc and Promotes Branch Migration.,Zhai B, DuPrez K, Doukov TI, Li H, Huang M, Shang G, Ni J, Gu L, Shen Y, Fan L J Mol Biol. 2017 Apr 7;429(7):1009-1029. doi: 10.1016/j.jmb.2017.02.016. Epub, 2017 Feb 24. PMID:28238763[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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