ID   MTSI_SPISQ              Reviewed;         386 AA.
AC   P15840;
DT   01-APR-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1993, sequence version 3.
DT   03-AUG-2022, entry version 96.
DE   RecName: Full=Orphan methyltransferase M.SssI {ECO:0000303|PubMed:12654995};
DE            Short=M.SssI {ECO:0000303|PubMed:2181400};
DE            EC=2.1.1.37 {ECO:0000269|PubMed:2181400};
DE   AltName: Full=CpG DNA methylase {ECO:0000303|PubMed:2181400};
DE   AltName: Full=Cytosine-specific methyltransferase SssI;
GN   Name=sssIM; Synonyms=mssSI;
OS   Spiroplasma monobiae (strain ATCC 33825 / MQ-1).
OC   Bacteria; Tenericutes; Mollicutes; Entomoplasmatales; Spiroplasmataceae;
OC   Spiroplasma.
OX   NCBI_TaxID=2136;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, AND CATALYTIC ACTIVITY.
RC   STRAIN=ATCC 33825 / MQ-1;
RX   PubMed=2181400; DOI=10.1093/nar/18.5.1145;
RA   Renbaum P., Abrahamove D., Fainsod A., Wilson G., Rottem S., Razin A.;
RT   "Cloning, characterization, and expression in Escherichia coli of the gene
RT   coding for the CpG DNA methylase from Spiroplasma sp. strain MQ1(M.SssI).";
RL   Nucleic Acids Res. 18:1145-1152(1990).
RN   [2]
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: This de novo methylase acts completely and exclusively on CG
CC       residues in DNA; methylates unmethylated and hemi-methylated DNA.
CC       {ECO:0000269|PubMed:2181400}.
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         Evidence={ECO:0000255|PROSITE-ProRule:PRU10018,
CC         ECO:0000269|PubMed:2181400};
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; X17195; CAA35058.1; -; Genomic_DNA.
DR   AlphaFoldDB; P15840; -.
DR   SMR; P15840; -.
DR   BindingDB; P15840; -.
DR   ChEMBL; CHEMBL4373; -.
DR   BRENDA; 2.1.1.37; 14199.
DR   PRO; PR:P15840; -.
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   Gene3D; 3.40.50.150; -; 1.
DR   InterPro; IPR018117; C5_DNA_meth_AS.
DR   InterPro; IPR001525; C5_MeTfrase.
DR   InterPro; IPR029063; SAM-dependent_MTases_sf.
DR   Pfam; PF00145; DNA_methylase; 1.
DR   PRINTS; PR00105; C5METTRFRASE.
DR   SUPFAM; SSF53335; SSF53335; 1.
DR   TIGRFAMs; TIGR00675; dcm; 1.
DR   PROSITE; PS00094; C5_MTASE_1; 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; Restriction system;
KW   S-adenosyl-L-methionine; Transferase.
FT   CHAIN           1..386
FT                   /note="Orphan methyltransferase M.SssI"
FT                   /id="PRO_0000087912"
FT   DOMAIN          11..386
FT                   /note="SAM-dependent MTase C5-type"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01016"
FT   ACT_SITE        141
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01016,
FT                   ECO:0000255|PROSITE-ProRule:PRU10018"
SQ   SEQUENCE   386 AA;  44313 MW;  B3EB188C09E78CDF CRC64;
     MSKVENKTKK LRVFEAFAGI GAQRKALEKV RKDEYEIVGL AEWYVPAIVM YQAIHNNFHT
     KLEYKSVSRE EMIDYLENKT LSWNSKNPVS NGYWKRKKDD ELKIIYNAIK LSEKEGNIFD
     IRDLYKRTLK NIDLLTYSFP CQDLSQQGIQ KGMKRGSGTR SGLLWEIERA LDSTEKNDLP
     KYLLMENVGA LLHKKNEEEL NQWKQKLESL GYQNSIEVLN AADFGSSQAR RRVFMISTLN
     EFVELPKGDK KPKSIKKVLN KIVSEKDILN NLLKYNLTEF KKTKSNINKA SLIGYSKFNS
     EGYVYDPEFT GPTLTASGAN SRIKIKDGSN IRKMNSDETF LYIGFDSQDG KRVNEIEFLT
     ENQKIFVCGN SISVEVLEAI IDKIGG