ID   MTAB_SYNP2              Reviewed;         139 AA.
AC   P34883;
DT   01-FEB-1994, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1994, sequence version 1.
DT   03-AUG-2022, entry version 107.
DE   RecName: Full=Type II methyltransferase M.AquIB {ECO:0000303|PubMed:12654995};
DE            Short=M.AquiB {ECO:0000303|PubMed:12654995};
DE            EC=2.1.1.37;
DE   AltName: Full=Cytosine-specific methyltransferase AquI subunit beta;
DE   AltName: Full=Modification methylase AquI subunit beta {ECO:0000303|PubMed:2104605};
DE            Short=M.AquI subunit beta {ECO:0000303|PubMed:2104605};
GN   Name=aquIMB; OrderedLocusNames=SYNPCC7002_A1188.1;
OS   Synechococcus sp. (strain ATCC 27264 / PCC 7002 / PR-6) (Agmenellum
OS   quadruplicatum).
OC   Bacteria; Cyanobacteria; Synechococcales; Synechococcaceae; Synechococcus;
OC   unclassified Synechococcus.
OX   NCBI_TaxID=32049;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, AND PROBABLE SUBUNIT.
RC   STRAIN=ATCC 27264 / PCC 7002 / PR-6;
RX   PubMed=2104605; DOI=10.1128/jb.172.1.266-272.1990;
RA   Karreman C., de Waard A.;
RT   "Agmenellum quadruplicatum M.AquI, a novel modification methylase.";
RL   J. Bacteriol. 172:266-272(1990).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 27264 / PCC 7002 / PR-6;
RA   Li T., Zhao J., Zhao C., Liu Z., Zhao F., Marquardt J., Nomura C.T.,
RA   Persson S., Detter J.C., Richardson P.M., Lanz C., Schuster S.C., Wang J.,
RA   Li S., Huang X., Cai T., Yu Z., Luo J., Zhao J., Bryant D.A.;
RT   "Complete sequence of Synechococcus sp. PCC 7002.";
RL   Submitted (FEB-2008) to the EMBL/GenBank/DDBJ databases.
RN   [3]
RP   NOMENCLATURE.
RX   PubMed=12654995; DOI=10.1093/nar/gkg274;
RA   Roberts R.J., Belfort M., Bestor T., Bhagwat A.S., Bickle T.A.,
RA   Bitinaite J., Blumenthal R.M., Degtyarev S.K., Dryden D.T., Dybvig K.,
RA   Firman K., Gromova E.S., Gumport R.I., Halford S.E., Hattman S.,
RA   Heitman J., Hornby D.P., Janulaitis A., Jeltsch A., Josephsen J., Kiss A.,
RA   Klaenhammer T.R., Kobayashi I., Kong H., Krueger D.H., Lacks S.,
RA   Marinus M.G., Miyahara M., Morgan R.D., Murray N.E., Nagaraja V.,
RA   Piekarowicz A., Pingoud A., Raleigh E., Rao D.N., Reich N., Repin V.E.,
RA   Selker E.U., Shaw P.C., Stein D.C., Stoddard B.L., Szybalski W.,
RA   Trautner T.A., Van Etten J.L., Vitor J.M., Wilson G.G., Xu S.Y.;
RT   "A nomenclature for restriction enzymes, DNA methyltransferases, homing
RT   endonucleases and their genes.";
RL   Nucleic Acids Res. 31:1805-1812(2003).
CC   -!- FUNCTION: A methylase, recognizes the double-stranded sequence 5'-
CC       CYCGRG-3', methylates C-1 on both strands, and protects the DNA from
CC       cleavage by the AquI endonuclease. {ECO:0000269|PubMed:2104605,
CC       ECO:0000303|PubMed:12654995}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a 2'-deoxycytidine in DNA + S-adenosyl-L-methionine = a 5-
CC         methyl-2'-deoxycytidine in DNA + H(+) + S-adenosyl-L-homocysteine;
CC         Xref=Rhea:RHEA:13681, Rhea:RHEA-COMP:11369, Rhea:RHEA-COMP:11370,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789,
CC         ChEBI:CHEBI:85452, ChEBI:CHEBI:85454; EC=2.1.1.37;
CC   -!- SUBUNIT: Heterodimer of an alpha and a beta subunit.
CC       {ECO:0000305|PubMed:2104605}.
CC   -!- DOMAIN: Corresponds to the C-terminal half of the enzymatic domain.
CC       {ECO:0000305|PubMed:2104605}.
CC   -!- SIMILARITY: Belongs to the class I-like SAM-binding methyltransferase
CC       superfamily. C5-methyltransferase family. {ECO:0000255|PROSITE-
CC       ProRule:PRU01016}.
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DR   EMBL; M28051; AAA22068.1; -; Genomic_DNA.
DR   EMBL; CP000951; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR   RefSeq; WP_012308460.1; NC_010475.1.
DR   AlphaFoldDB; P34883; -.
DR   SMR; P34883; -.
DR   REBASE; 3283; M.AquI.
DR   PRO; PR:P34883; -.
DR   Proteomes; UP000001688; Chromosome.
DR   GO; GO:0003886; F:DNA (cytosine-5-)-methyltransferase activity; IEA:UniProtKB-EC.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0009307; P:DNA restriction-modification system; IEA:UniProtKB-KW.
DR   InterPro; IPR001525; C5_MeTfrase.
DR   InterPro; IPR031303; C5_meth_CS.
DR   InterPro; IPR029063; SAM-dependent_MTases_sf.
DR   Pfam; PF00145; DNA_methylase; 1.
DR   SUPFAM; SSF53335; SSF53335; 1.
DR   PROSITE; PS00095; C5_MTASE_2; 1.
DR   PROSITE; PS51679; SAM_MT_C5; 1.
PE   1: Evidence at protein level;
KW   DNA-binding; Methyltransferase; Reference proteome; Restriction system;
KW   S-adenosyl-L-methionine; Transferase.
FT   CHAIN           1..139
FT                   /note="Type II methyltransferase M.AquIB"
FT                   /id="PRO_0000087855"
FT   DOMAIN          1..135
FT                   /note="SAM-dependent MTase C5-type"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01016"
FT   REGION          38..58
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   139 AA;  15760 MW;  8550B7E0194CE006 CRC64;
     MDIKNVHIKN HEQTAHAPST LEKIRKVKQG GKLSEQTKTF GSTYRRLDPN QPSPTVTRSG
     YRDFIHPFED RMLTVRELAC LQTFPLDWEF TGTRLDSYSS KRKVTMTQFG QVGNAVPPLL
     AEAVAKAVSE QLLDVIDEK