CSM2_STRTR
ID CSM2_STRTR Reviewed; 121 AA.
AC A0A0A7HIX1;
DT 16-JAN-2019, integrated into UniProtKB/Swiss-Prot.
DT 04-MAR-2015, sequence version 1.
DT 25-MAY-2022, entry version 17.
DE RecName: Full=CRISPR system Cms protein Csm2;
DE AltName: Full=CRISPR type III A-associated protein Csm2;
GN Name=csm2 {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).
RN [3]
RP SUBUNIT.
RC STRAIN=DGCC8004;
RX PubMed=28663439; DOI=10.1126/science.aao0100;
RA Kazlauskiene M., Kostiuk G., Venclovas C., Tamulaitis G., Siksnys V.;
RT "A cyclic oligonucleotide signaling pathway in type III CRISPR-Cas
RT systems.";
RL Science 357:605-609(2017).
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 subunit may be involved in monitoring complementarity of
CC crRNA and target RNA. {ECO:0000305|PubMed:27105119}.
CC -!- SUBUNIT: Part of the Csm effector complex that includes at least
CC Cas10(1), Csm2(3), Csm3(5), Csm4(1), Csm5(1) and mature crRNA
CC (PubMed:25458845, PubMed:27105119, PubMed:28663439). The Csm complex is
CC elongated and slightly twisted with a maximal length of 215 Angstroms
CC and a diameter of 75-80 Angstroms (PubMed:25458845). It has been
CC modeled to have a central protein filamant of Csm3 subunits along which
CC the dsRNA helix of paired crRNA and target RNA binds. The filament is
CC capped at one end by Cas10 and Csm4 and at the other end by Csm5; ssDNA
CC is thought to bind to the N-terminal HD domain of Cas10 (Probable). Csm
CC with a precursor crRNA does not include Csm5, while Cas6, the enzyme
CC probably involved in pre-crRNA processing, is found associated with a
CC subset of the Csm complex (PubMed:25458845).
CC {ECO:0000269|PubMed:25458845, ECO:0000269|PubMed:27105119,
CC ECO:0000269|PubMed:28663439, 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 Csm2 family.
CC {ECO:0000305}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; KM222358; AIZ03605.1; -; Genomic_DNA.
DR PDB; 6NUD; EM; 3.50 A; A/B/M=1-121.
DR PDB; 6NUE; EM; 3.30 A; A/B/M=1-121.
DR PDBsum; 6NUD; -.
DR PDBsum; 6NUE; -.
DR AlphaFoldDB; A0A0A7HIX1; -.
DR SMR; A0A0A7HIX1; -.
DR GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR GO; GO:0051607; P:defense response to virus; IEA:UniProtKB-KW.
DR CDD; cd09647; Csm2_III-A; 1.
DR InterPro; IPR010149; CRISPR-assoc_prot_Csm2_III-A.
DR Pfam; PF03750; Csm2_III-A; 1.
DR TIGRFAMs; TIGR01870; cas_TM1810_Csm2; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Antiviral defense; RNA-binding.
FT CHAIN 1..121
FT /note="CRISPR system Cms protein Csm2"
FT /id="PRO_0000446117"
FT TURN 15..21
FT /evidence="ECO:0007829|PDB:6NUE"
FT STRAND 24..27
FT /evidence="ECO:0007829|PDB:6NUE"
FT TURN 34..37
FT /evidence="ECO:0007829|PDB:6NUE"
FT HELIX 38..41
FT /evidence="ECO:0007829|PDB:6NUE"
FT HELIX 43..49
FT /evidence="ECO:0007829|PDB:6NUE"
FT TURN 54..57
FT /evidence="ECO:0007829|PDB:6NUE"
FT HELIX 58..71
FT /evidence="ECO:0007829|PDB:6NUE"
FT TURN 72..74
FT /evidence="ECO:0007829|PDB:6NUE"
FT HELIX 76..85
FT /evidence="ECO:0007829|PDB:6NUE"
FT HELIX 87..93
FT /evidence="ECO:0007829|PDB:6NUE"
FT HELIX 97..117
FT /evidence="ECO:0007829|PDB:6NUE"
SQ SEQUENCE 121 AA; 14217 MW; 0107C4C036AE7CCF CRC64;
MAILTDENYV DKAERAISLL EKDNKGNYLL TTSQIRKLLS LCSSLYDRSK ERKFDELIND
VSYLRVQFVY QAGREIAVKD LIEKAQILEA LKEIKDRETL QRFCRYMEAL VAYFKFYGGK
D
