CAS6_STRTR
ID CAS6_STRTR Reviewed; 243 AA.
AC A0A0A7HF73;
DT 16-JAN-2019, integrated into UniProtKB/Swiss-Prot.
DT 04-MAR-2015, sequence version 1.
DT 25-MAY-2022, entry version 21.
DE RecName: Full=CRISPR-associated endoribonuclease Cas6;
DE EC=3.1.-.-;
DE AltName: Full=Cas6 endoRNase;
DE AltName: Full=Cas6 endoribonuclease;
GN Name=cas6 {ECO:0000303|PubMed:25458845};
OS Streptococcus thermophilus.
OC Bacteria; Firmicutes; Bacilli; Lactobacillales; Streptococcaceae;
OC Streptococcus.
OX NCBI_TaxID=1308;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION IN PHAGE RESISTANCE, TARGETS
RP SSRNA, SUBUNIT, AND ANTIVIRAL DEFENSE.
RC STRAIN=DGCC8004;
RX PubMed=25458845; DOI=10.1016/j.molcel.2014.09.027;
RA Tamulaitis G., Kazlauskiene M., Manakova E., Venclovas C., Nwokeoji A.O.,
RA Dickman M.J., Horvath P., Siksnys V.;
RT "Programmable RNA shredding by the type III-A CRISPR-Cas system of
RT Streptococcus thermophilus.";
RL Mol. Cell 56:506-517(2014).
RN [2]
RP FUNCTION, AND SUBUNIT.
RC STRAIN=DGCC8004;
RX PubMed=27105119; DOI=10.1016/j.molcel.2016.03.024;
RA Kazlauskiene M., Tamulaitis G., Kostiuk G., Venclovas C., Siksnys V.;
RT "Spatiotemporal control of type III-A CRISPR-Cas immunity: coupling DNA
RT degradation with the target RNA recognition.";
RL Mol. Cell 62:295-306(2016).
CC -!- FUNCTION: CRISPR (clustered regularly interspaced short palindromic
CC repeat) is an adaptive immune system that provides protection against
CC mobile genetic elements (viruses, transposable elements and conjugative
CC plasmids). CRISPR clusters contain spacers, sequences complementary to
CC antecedent mobile elements, and target invading nucleic acids. CRISPR
CC clusters are transcribed and processed into CRISPR RNA (crRNA). The
CC type III-A Csm effector complex binds crRNA and acts as a crRNA-guided
CC RNase, DNase and cyclic oligoadenylate synthase; binding of target RNA
CC cognate to the crRNA is required for all activities. In a heterologous
CC host this Csm effector complex restricts ssRNA phage MS2, suggesting it
CC may target RNA viruses in vivo. {ECO:0000269|PubMed:25458845}.
CC -!- FUNCTION: Csm functions as a non-specific ssDNase. Base-pairing between
CC crRNA and target RNA to form a ternary Csm complex activates a ssDNase
CC activity; target RNA cleavage suppresses the ssDNase, a temporal
CC control that prevents uncontrolled DNA degradation. Viral RNA
CC transcripts probably tether the Csm complex to the viral genome,
CC recruiting Cas10 ssDNA activity which is able to degrade DNA in the
CC transcription bubble, spatially controlling the DNase activity.
CC {ECO:0000269|PubMed:27105119}.
CC -!- FUNCTION: This protein processes pre-crRNA into individual crRNA units.
CC {ECO:0000250|UniProtKB:Q53WG9}.
CC -!- SUBUNIT: Part of the Csm effector complex that includes at least
CC Cas10(1), Csm2(3), Csm3(5), Csm4(1); the presence of Csm5 and Cas6 may
CC depend on the processing state of precursor crRNA (PubMed:25458845).
CC Csm with a precursor crRNA does not include Csm5, while Cas6, the
CC enzyme probably involved in pre-crRNA processing, is found associated
CC with a subset of the Csm complex that is probably in the process of
CC pre-crRNA maturation (Probable). The Csm complex is elongated and
CC slightly twisted with a maximal length of 215 Angstroms and a diameter
CC of 75-80 Angstroms (PubMed:25458845). It has been modeled to have a
CC central protein filamant of Csm3 subunits along which the dsRNA helix
CC of paired crRNA and target RNA binds. The filament is capped at one end
CC by Cas10 and Csm4 and at the other end by Csm5; ssDNA is thought to
CC bind to the N-terminal HD domain of Cas10 (Probable).
CC {ECO:0000269|PubMed:25458845, ECO:0000305|PubMed:25458845,
CC ECO:0000305|PubMed:27105119}.
CC -!- MISCELLANEOUS: Encoded in a type III-A CRISPR locus.
CC {ECO:0000269|PubMed:25458845}.
CC -!- SIMILARITY: Belongs to the CRISPR-associated endoribonuclease Cas6
CC family. {ECO:0000305}.
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DR EMBL; KM222358; AIZ03603.1; -; Genomic_DNA.
DR RefSeq; WP_014621546.1; NZ_CP049053.1.
DR PDB; 6FJW; X-ray; 2.70 A; A=1-243.
DR PDBsum; 6FJW; -.
DR AlphaFoldDB; A0A0A7HF73; -.
DR SMR; A0A0A7HF73; -.
DR STRING; 322159.STER_0972; -.
DR GO; GO:0004519; F:endonuclease activity; IEA:UniProtKB-KW.
DR GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR GO; GO:0051607; P:defense response to virus; IEA:UniProtKB-KW.
DR InterPro; IPR019267; CRISPR-assoc_Cas6_C.
DR InterPro; IPR010156; CRISPR-assoc_prot_Cas6.
DR Pfam; PF10040; CRISPR_Cas6; 1.
DR TIGRFAMs; TIGR01877; cas_cas6; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Antiviral defense; Endonuclease; Hydrolase; Nuclease;
KW RNA-binding.
FT CHAIN 1..243
FT /note="CRISPR-associated endoribonuclease Cas6"
FT /id="PRO_0000446115"
FT STRAND 2..9
FT /evidence="ECO:0007829|PDB:6FJW"
FT HELIX 15..27
FT /evidence="ECO:0007829|PDB:6FJW"
FT HELIX 32..38
FT /evidence="ECO:0007829|PDB:6FJW"
FT STRAND 41..43
FT /evidence="ECO:0007829|PDB:6FJW"
FT STRAND 45..52
FT /evidence="ECO:0007829|PDB:6FJW"
FT STRAND 54..63
FT /evidence="ECO:0007829|PDB:6FJW"
FT HELIX 66..78
FT /evidence="ECO:0007829|PDB:6FJW"
FT STRAND 94..99
FT /evidence="ECO:0007829|PDB:6FJW"
FT HELIX 102..109
FT /evidence="ECO:0007829|PDB:6FJW"
FT STRAND 116..126
FT /evidence="ECO:0007829|PDB:6FJW"
FT STRAND 131..137
FT /evidence="ECO:0007829|PDB:6FJW"
FT HELIX 140..154
FT /evidence="ECO:0007829|PDB:6FJW"
FT HELIX 163..171
FT /evidence="ECO:0007829|PDB:6FJW"
FT STRAND 173..182
FT /evidence="ECO:0007829|PDB:6FJW"
FT STRAND 195..203
FT /evidence="ECO:0007829|PDB:6FJW"
FT HELIX 207..223
FT /evidence="ECO:0007829|PDB:6FJW"
FT STRAND 225..227
FT /evidence="ECO:0007829|PDB:6FJW"
FT HELIX 229..231
FT /evidence="ECO:0007829|PDB:6FJW"
FT STRAND 236..238
FT /evidence="ECO:0007829|PDB:6FJW"
SQ SEQUENCE 243 AA; 28281 MW; 86F43A6B4E1B333E CRC64;
MKKLVFTFKR IDHPAQDLAV KFHGFLMEQL DSDYVDYLHQ QQTNPYATKV IQGKENTQWV
VHLLTDDHED KVFMTLLQIK EVSLNDLPKL SVEKVEIQEL GADKLLEIFN SEENQTYFSI
IFETPTGFKS QGSYVIFPSM RLIFQSLMQK YGRLVENQPE IEEDTLDYLS EHSTITNYRL
ETSYFRVHRQ RIPAFRGKLT FKVQGAKTLK AYVKMLLTFG EYSGLGMKTS LGMGGIKLEE
RKD
