4zdt | pdb_00004zdt
Crystal structure of the RING finger domain of Slx1 in complex with the C-terminal domain of Slx4
Structural highlights
Function[SLX1_SCHPO] Catalytic subunit of the slx1-slx4 structure-specific endonuclease that resolves DNA secondary structures generated during DNA repair and recombination. Has endonuclease activity towards branched DNA substrates, introducing single-strand cuts in duplex DNA close to junctions with ss-DNA. Has a preference for stem-loop (SL) and splayed arm Y structures. Introduces a single-strand cut in duplex DNA on the 3' side of a double-strand/single-strand junction with respect to the single-strand moving 3' to 5' away from the junction. Plays a critical role in maintaining the integrity of the ribosomal DNA (rDNA) loci, where it has a role in re-starting stalled replication forks. The complex initiates homologous recombination (HR) events, used to maintain rDNA copy number, in the rDNA repeats that are processed by a mechanism that requires rad22, but not rhp51. It is also required for suppression of methyl methanesulfonate (MMS) and UV-C irradiation hypersensitivity of the structural maintenance of chromosome (SMC) protein mutant, smc6-74, by overexpression of brc1. Has Holliday junction resolvase activity in vitro.[HAMAP-Rule:MF_03100][1] [2] [3] [4] [5] [SLX4_SCHPO] Regulatory subunit of the slx1-slx4 structure-specific endonuclease that resolves DNA secondary structures generated during DNA repair and recombination. Has endonuclease activity towards branched DNA substrates, introducing single-strand cuts in duplex DNA close to junctions with ss-DNA. Has a preference for stem-loop (SL) and splayed arm Y structures. Introduces a single-strand cut in duplex DNA on the 3' side of a double-strand/single-strand junction with respect to the single-strand moving 3' to 5' away from the junction. Plays a critical role in maintaining the integrity of the ribosomal DNA (rDNA) loci, where it has a role in re-starting stalled replication forks. The complex initiates homologous recombination (HR) events, used to maintain rDNA copy number, in the rDNA repeats that are processed by a mechanism that requires rad22, but not rhp51. Has Holliday junction resolvase activity in vitro. Slx4 is required for efficient processing of DNA substrates.[6] [7] Publication Abstract from PubMedThe SLX1-SLX4 complex is a structure-specific endonuclease that cleaves branched DNA structures and plays significant roles in DNA recombination and repair in eukaryotic cells. The heterodimeric interaction between SLX1 and SLX4 is essential for the endonuclease activity of SLX1. Here, we present the crystal structure of Slx1 C-terminal zinc finger domain in complex with the C-terminal helix-turn-helix domain of Slx4 from Schizosaccharomyces pombe at 2.0 A resolution. The structure reveals a conserved binding mechanism underling the Slx1-Slx4 interaction. Structural and sequence analyses indicate Slx1 C-terminal domain is actually an atypical C4HC3-type RING finger which normally possesses E3 ubiquitin ligase activity, but here is absolutely required for Slx1 interaction with Slx4. Furthermore, we found the C-terminal tail of S. pombe Slx1 contains a SUMO-interacting motif and can recognize Pmt3 (S. pombe SUMO), suggesting that Slx1-Slx4 complex could be recruited by SUMOylated protein targets to take part in replication associated DNA repair processes. Crystal structure and SUMO binding of Slx1-Slx4 complex.,Lian FM, Xie S, Qian C Sci Rep. 2016 Jan 20;6:19331. doi: 10.1038/srep19331. PMID:26787556[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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