ID   CSA2B_SACS2             Reviewed;         321 AA.
AC   Q97Y91;
DT   13-JUN-2012, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2001, sequence version 1.
DT   25-MAY-2022, entry version 91.
DE   RecName: Full=CRISPR-associated aCascade subunit Cas7/Csa2 2;
DE   AltName: Full=CRISPR-associated aCascade subunit Cas7/Csa2, subtype I-A/Apern 2;
GN   Name=csa2b; Synonyms=cas7b; OrderedLocusNames=SSO1442;
OS   Saccharolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2)
OS   (Sulfolobus solfataricus).
OC   Archaea; Crenarchaeota; Thermoprotei; Sulfolobales; Sulfolobaceae;
OC   Saccharolobus.
OX   NCBI_TaxID=273057;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 35092 / DSM 1617 / JCM 11322 / P2;
RX   PubMed=11427726; DOI=10.1073/pnas.141222098;
RA   She Q., Singh R.K., Confalonieri F., Zivanovic Y., Allard G., Awayez M.J.,
RA   Chan-Weiher C.C.-Y., Clausen I.G., Curtis B.A., De Moors A., Erauso G.,
RA   Fletcher C., Gordon P.M.K., Heikamp-de Jong I., Jeffries A.C., Kozera C.J.,
RA   Medina N., Peng X., Thi-Ngoc H.P., Redder P., Schenk M.E., Theriault C.,
RA   Tolstrup N., Charlebois R.L., Doolittle W.F., Duguet M., Gaasterland T.,
RA   Garrett R.A., Ragan M.A., Sensen C.W., Van der Oost J.;
RT   "The complete genome of the crenarchaeon Sulfolobus solfataricus P2.";
RL   Proc. Natl. Acad. Sci. U.S.A. 98:7835-7840(2001).
RN   [2]
RP   X-RAY CRYSTALLOGRAPHY (2.00 ANGSTROMS), SUBUNIT, RNA-BINDING, INTERACTION
RP   WITH CAS5E, AND MUTAGENESIS OF HIS-160.
RC   STRAIN=ATCC 35091 / DSM 1616 / JCM 8930 / NBRC 15331 / P1, and
RC   ATCC 35092 / DSM 1617 / JCM 11322 / P2;
RX   PubMed=21507944; DOI=10.1074/jbc.m111.238485;
RA   Lintner N.G., Kerou M., Brumfield S.K., Graham S., Liu H., Naismith J.H.,
RA   Sdano M., Peng N., She Q., Copie V., Young M.J., White M.F., Lawrence C.M.;
RT   "Structural and functional characterization of an archaeal clustered
RT   regularly interspaced short palindromic repeat (CRISPR)-associated complex
RT   for antiviral defense (CASCADE).";
RL   J. Biol. Chem. 286:21643-21656(2011).
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) (By
CC       similarity). {ECO:0000250}.
CC   -!- SUBUNIT: Part of the aCascade ribonucleoprotein complex, minimally
CC       composed of Csa2 and Cas5a, which binds crRNA. Other possible
CC       components of aCascade in strain P1 are Cas6b (SSO1437) and Csa5
CC       (SSO1443), while SSO1399, Cas5b (SSO1400) and SSO1401 have sometimes
CC       been seen weakly associated. Csa2 is probably the major RNA-binding
CC       subunit. The Csa2-Cas5a-crRNA complex also binds target DNA homologous
CC       to crRNA, probably forming an R-loop. Purified aCascade forms a
CC       filament about 6 nm in width. {ECO:0000269|PubMed:21507944}.
CC   -!- MISCELLANEOUS: Crystallography and cloning were done with strain P2,
CC       while interaction experiments were done with genes cloned from strain
CC       P2 but over-expressed in P1. The aCascade complex was purified from
CC       strain P1.
CC   -!- SIMILARITY: Belongs to the CRISPR-associated protein Cas7/Cst2/DevR
CC       family. Subtype I-a/Apern subfamily. {ECO:0000305}.
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DR   EMBL; AE006641; AAK41675.1; -; Genomic_DNA.
DR   PIR; D90302; D90302.
DR   RefSeq; WP_010923407.1; NC_002754.1.
DR   PDB; 3PS0; X-ray; 2.00 A; A/B/C/D=1-321.
DR   PDBsum; 3PS0; -.
DR   AlphaFoldDB; Q97Y91; -.
DR   SMR; Q97Y91; -.
DR   STRING; 273057.SSO1442; -.
DR   EnsemblBacteria; AAK41675; AAK41675; SSO1442.
DR   GeneID; 27427810; -.
DR   KEGG; sso:SSO1442; -.
DR   PATRIC; fig|273057.12.peg.1471; -.
DR   eggNOG; arCOG03617; Archaea.
DR   HOGENOM; CLU_054331_0_0_2; -.
DR   InParanoid; Q97Y91; -.
DR   PhylomeDB; Q97Y91; -.
DR   Proteomes; UP000001974; Chromosome.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0051607; P:defense response to virus; IEA:UniProtKB-KW.
DR   InterPro; IPR002764; Cas7/Cst2/DevR_sub_I-a/Apern.
DR   InterPro; IPR010154; CRISPR-assoc_Cas7/Cst2/DevR.
DR   Pfam; PF01905; DevR; 1.
DR   TIGRFAMs; TIGR01875; cas_MJ0381; 1.
DR   TIGRFAMs; TIGR02583; DevR_archaea; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Antiviral defense; Reference proteome; RNA-binding.
FT   CHAIN           1..321
FT                   /note="CRISPR-associated aCascade subunit Cas7/Csa2 2"
FT                   /id="PRO_0000417885"
FT   MUTAGEN         160
FT                   /note="H->A: Significantly reduced affinity for crRNA."
FT                   /evidence="ECO:0000269|PubMed:21507944"
FT   STRAND          1..11
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           12..15
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   STRAND          24..26
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   STRAND          28..36
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   STRAND          39..48
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           50..68
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           76..78
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           87..93
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           101..103
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           104..114
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           116..120
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   STRAND          123..125
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   STRAND          127..129
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   STRAND          131..133
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   STRAND          136..140
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   STRAND          142..144
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           151..158
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   STRAND          180..190
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           192..194
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           207..224
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           226..230
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   STRAND          245..257
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   STRAND          264..266
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           269..283
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   STRAND          289..297
FT                   /evidence="ECO:0007829|PDB:3PS0"
FT   HELIX           311..319
FT                   /evidence="ECO:0007829|PDB:3PS0"
SQ   SEQUENCE   321 AA;  35265 MW;  0B5959530AC2709A CRC64;
     MISGSVRFLV NLESLNGVES IGNLTKHRTA PVVLKTSTGY LVRYVPVISG EALAHAYQAS
     LVDIAKKEGL PVGSLSSQYE FIKFSTDEAL KIEGIKEPKD YNDARRFEVE VMLKDVIADV
     GGFMYAGGAP VRRTSRIKLG YMIPALRGDE IPAQLEAQFH VRFSNKPVSG SQAIFNVEVS
     SALYTFSFEL DEDLIAVPST FGEKVKGEEE LERQKAKRVK SAIKALYSLL SGNFGGKRSR
     FLPSMKLMSL VVTKTDFPFM PEPAHDDDYI KTTIMRLGKA KGVLNGNLAK AYVINNEGIE
     VGEGVTVLST VEDLVVKLEE E