Protein: Protein argonaute (Q31N05)
Organism: Synechococcus elongatus (strain ATCC 33912 / PCC 7942 / FACHB-805)
Function: A DNA-guided ssDNA endonuclease that might play a role in defense against invading mobile genetic elements. Uses short ssDNA sequences as guides (gDNA) to bind complementary target strands, resulting in cleavage of the target DNA (tDNA). The cleavage site is 10 nucleotides (nt) downstream of the target residue base-paired with the 5'-end of the gDNA. Both 5'-P and 5'-OH gDNAs confer activity; a 5'-OH guide cleaves between nt 10-11 and nt 11-12. Guide DNA mismatches in the seed (nt 2-9) can enhance activity, mismatches 1-5 nt after the cleavage site block activity. Has no appreciable activity with guide RNA or on target RNA. In situ binds to 5'-phosphorylated DNA 14-20 nt in length; small DNA maps over the chromosome and plasmid with some preference for the replication origin and the probable termination site. Also has weak guide-independent nuclease activity on DNA called 'chopping'. Overexpression of wild-type or catalytically inactive mutant has no visible effect during growth under continuous high light for up to a month
Sequence: MDLLSNLRRSSIVLNRFYVKSLSQSDLTAYEYRCIFKKTPELGDEKRLLASICYKLGAIAVRIGSNIITKEAVRPEKLQGHDWQLVQMGTKQLDCRNDAHRCALETFERKFLERDLSASSQTEVRKAAEGGLIWWVVGAKGIEKSGNGWEVHRGRRIDVSLDAEGNLYLEIDIHHRFYTPWTVHQWLEQYPEIPLSYVRNNYLDERHGFINWQYGRFTQERPQDILLDCLGMSLAEYHLNKGATEEEVQQSYVVYVKPISWRKGKLTAHLSRRLSPSLTMEMLAKVAEDSTVCDREKREIRAVFKSIKQSINQRLQEAQKTASWILTKTYGISSPAIALSCDGYLLPAAKLLAANKQPVSKTADIRNKGCAKIGETSFGYLNLYNNQLQYPLEVHKCLLEIANKNNLQLSLDQRRVLSDYPQDDLDQQMFWQTWSSQGIKTVLVVMPWDSHHDKQKIRIQAIQAGIATQFMVPLPKADKYKALNVTLGLLCKAGWQPIQLESVDHPEVADLIIGFDTGTNRELYYGTSAFAVLADGQSLGWELPAVQRGETFSGQAIWQTVSKLIIKFYQICQRYPQKLLLMRDGLVQEGEFQQTIELLKERKIAVDVISVRKSGAGRMGQEIYENGQLVYRDAAIGSVILQPAERSFIMVTSQPVSKTIGSIRPLRIVHEYGSTDLELLALQTYHLTQLHPASGFRSCRLPWVLHLADRSSKEFQRIGQISVLQNISRDKLIAV
InterPro domains: - IPR040895: Argonaute, PAZ domain (domain) [185-276]
- IPR003165: Piwi domain (domain) [441-720]
- IPR036397: Ribonuclease H superfamily (homologous_superfamily) [507-735]
- IPR012337: Ribonuclease H-like superfamily (homologous_superfamily) [307-732]
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:0034641 (cellular nitrogen compound metabolic process), GO:1901360 (organic cyclic compound metabolic process), GO:0044260 (cellular macromolecule metabolic process), GO:0006139 (nucleobase-containing compound metabolic process), GO:0043170 (macromolecule metabolic process), GO:0046483 (heterocycle metabolic process), GO:0006259 (DNA metabolic process), GO:0090304 (nucleic acid metabolic process), GO:0006260 (DNA replication), GO:0006261 (DNA-templated DNA replication)
Cellular Component (CC): GO:0005575 (cellular component), GO:0032991 (protein-containing complex), GO:1902494 (catalytic complex), GO:0140535 (intracellular protein-containing complex), GO:1905348 (endonuclease complex), GO:1902555 (endoribonuclease complex)