Protein: Protein argonaute (Q58717)
Organism: Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM
Function: A DNA-guided ssDNA endonuclease that may play a role in defense against invading genetic elements. Uses short ssDNA sequences as guides (gDNA) to bind complementary target strands, resulting in slicing of the target DNA (tDNA). Endonucleolytically cleaves tDNA (the gDNA indicates where to cleave); two major and two minor products are seen which correspond to cleavage sites between nucleotides 9/10, 10/11, 13/14, and 14/15 downstream of the target residue base-paired with the 5'-end of the gDNA. Efficient guide-dependent tDNA cleavage requires a minimal length of 15 bp and is maximal at 19 bp. Prefers gDNA with 5'-phosphorylated purines and 3'- pyrimidines; changing these bases alters the cleavage activity and patterns. Also has guide-independent activity on tDNA called 'chopping'. Probably a first round of guide- independent activity on an invading plasmid or virus would generate guide DNAs for subsequent, more efficient, guide-dependent degradation of invading nucleic acids. Has no activity on substrate with a mismatch at positions 10 and 11, on ssDNA or RNA, nor on DNA:RNA hybrids. Digests longer (750 bp) dsDNA as well as circular plasmid and naked genomic DNA, but not chromatin, in a guide DNA-independent manner. Addition of endogenous histone A3 protects DNA from cleavage, while cleavage is insensitive to methylation. When plasmid encoding active or mutated protein (Ala-541) is transformed into Sulfolobus acidocaldarius about 25-fold fewer transformants are found with active protein; reduced levels of plasmid are found in wild-type transformed cells. While S.acidocaldarius grows at a similar temperature to M.jannaschii (70 to 80 degrees Celsius) it has very different histone-like proteins, which presumably do not protect against MjAgo. Binds ssDNA, dsDNA and DNA-RNA hybrids; binding is most efficient with dsDNA
Sequence: MVLNKVTYKINAYKIKEEFIPKEVHFYRIKSFVNEAFNFYRFVNFYGGMIINKKDKSFVLPYKVDNKVLKYKDGNNEIPIDIEYIKSLKLEYVKPEIAEKLVRGYLKSVHKIEPELSRIIKNIRKHKVVENIKVESYCEYEVKKHDGDYYLILNFRHTASITKHLWDFVNRDKALLEEYVGKKIIFKPNPKVRYTISLVDAPNPQKIEEIMSHIIKYYKWSEDMVKSTFGEIDYNQPIMYCEEILEPFAPQFCNLVFYMDELDSYILKELQSYWRLSNENKGKIINEIAKKLRFIDNTPKELEFMKFNNTPLLVKDVNKNPTKIYSTNTLFTWIYNQNAKIYLPYDVPEIIRNKNLLTYILIDEEIKDELKAIKDKVNKMFRNYNKIANKTELPKFNYANRWKYFSTDDIRGIIKEIKSEFNDEICFALIIGKEKYKDNDYYEILKKQLFDLKIISQNILWENWRKDDKGYMTNNLLIQIMGKLGIKYFILDSKTPYDYIMGLDTGLGIFGNHRVGGCTVVYDSEGKIRRIQPIETPAPGERLHLPYVIEYLENKANIDMENKNILFLRDGFIQNSERNDLKEISKELNSNIEVISIRKNNKYKVFTSDYRIGSVFGNDGIFLPHKTPFGSNPVKLSTWLRFNCGNEEGLKINESIMQLLYDLTKMNYSALYGEGRYLRIPAPIHYADKFVKALGKNWKIDEELLKHGFLYFI
InterPro domains: - IPR003100: PAZ domain (domain) [164-257]
- IPR054390: Argonaute, N-terminal domain, archaea (domain) [22-90]
- IPR012337: Ribonuclease H-like superfamily (homologous_superfamily) [301-713]
- IPR003165: Piwi domain (domain) [426-699]
- IPR054436: Argonaute, PAZ domain, methanocaldococcus (domain) [163-258]
- IPR036085: PAZ domain superfamily (homologous_superfamily) [5-305]
- IPR036397: Ribonuclease H superfamily (homologous_superfamily) [494-713]
Interaction partners: - Uncharacterized protein MJ0398
- Reverse gyrase
- DNA double-strand break repair protein Mre11
- DNA double-strand break repair Rad50 ATPase
- Ribonuclease VapC4
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0005488 (binding), GO:0005515 (protein binding)
Biological Process (BP): GO:0008150 (biological process), GO:0008152 (metabolic process), GO:0009987 (cellular process), GO:0044237 (cellular metabolic process), GO:0071704 (organic substance metabolic process), GO:0044238 (primary metabolic process), GO:0006807 (nitrogen compound metabolic process), GO:0006725 (cellular aromatic compound metabolic process), GO:1901360 (organic cyclic compound metabolic process), GO:0034641 (cellular nitrogen compound metabolic process), GO:0006139 (nucleobase-containing compound metabolic process), GO:0043170 (macromolecule metabolic process), GO:0046483 (heterocycle metabolic process), GO:0090304 (nucleic acid metabolic process), GO:0010467 (gene expression), GO:0016070 (RNA metabolic process), GO:0006396 (RNA processing), GO:0006397 (mRNA processing), GO:0016071 (mRNA metabolic process), GO:0036260 (RNA capping), GO:0006370 (7-methylguanosine mRNA capping), GO:0009452 (7-methylguanosine RNA capping)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0018995 (host cellular component), GO:0043657 (host cell), GO:0033643 (host cell part), GO:0033646 (host intracellular part), GO:0043656 (host intracellular region), GO:0030430 (host cell cytoplasm), GO:0033655 (host cell cytoplasm part), GO:0033647 (host intracellular organelle), GO:0033648 (host intracellular membrane-bounded organelle)