7zes
From Proteopedia
Human SLFN11 dimer bound to ssDNA
Structural highlights
Function[SLN11_HUMAN] Inhibitor of DNA replication that promotes cell death in response to DNA damage (PubMed:22927417, PubMed:26658330, PubMed:29395061). Acts as a guardian of the genome by killing cells with defective replication (PubMed:29395061). Persistently blocks stressed replication forks by opening chromatin across replication initiation sites at stressed replication forks, possibly leading to unwind DNA ahead of the MCM helicase and block fork progression, ultimately leading to cell death (PubMed:29395061). Acts independently of ATR (PubMed:29395061). Also acts as an interferon (IFN)-induced antiviral protein which acts as an inhibitor of retrovirus protein synthesis (PubMed:23000900). Specifically abrogates the production of retroviruses such as human immunodeficiency virus 1 (HIV-1) by acting as a specific inhibitor of the synthesis of retroviruses encoded proteins in a codon-usage-dependent manner (PubMed:23000900). Binds to tRNAs and exploits the unique viral codon bias towards A/T nucleotides (PubMed:23000900). The exact inhibition mechanism is unclear: may either sequester tRNAs, prevent their maturation via post-transcriptional processing or may accelerate their deacylation (PubMed:23000900). Does not inhibit reverse transcription, integration or production and nuclear export of viral RNA (PubMed:23000900).[1] [2] [3] [4] Publication Abstract from PubMedSchlafen 11 (SLFN11) is an interferon-inducible antiviral restriction factor with tRNA endoribonuclease and DNA binding functions. It is recruited to stalled replication forks in response to replication stress and inhibits replication of certain viruses such as the human immunodeficiency virus 1 (HIV-1) by modulating the tRNA pool. SLFN11 has been identified as a predictive biomarker in cancer, as its expression correlates with a beneficial response to DNA damage inducing anticancer drugs. However, the mechanism and interdependence of these two functions are largely unknown. Here, we present cryo-electron microscopy (cryo-EM) structures of human SLFN11 in its dimeric apoenzyme state, bound to tRNA and in complex with single-strand DNA. Full-length SLFN11 neither hydrolyses nor binds ATP and the helicase domain appears in an autoinhibited state. Together with biochemical and structure guided mutagenesis studies, our data give detailed insights into the mechanism of endoribonuclease activity as well as suggestions on how SLFN11 may block stressed replication forks. Mechanistic understanding of human SLFN11.,Metzner FJ, Wenzl SJ, Kugler M, Krebs S, Hopfner KP, Lammens K Nat Commun. 2022 Sep 17;13(1):5464. doi: 10.1038/s41467-022-33123-0. PMID:36115853[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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