T1S_SALPO
ID T1S_SALPO Reviewed; 463 AA.
AC P07990;
DT 01-AUG-1988, integrated into UniProtKB/Swiss-Prot.
DT 01-AUG-1988, sequence version 1.
DT 03-AUG-2022, entry version 62.
DE RecName: Full=Type I restriction enzyme StySPI specificity subunit {ECO:0000303|PubMed:3025838};
DE Short=S protein {ECO:0000303|PubMed:3025838};
DE AltName: Full=Type I restriction and modification system SP {ECO:0000303|PubMed:3025838};
DE AltName: Full=Type I specificity subunit S.StySPI {ECO:0000303|PubMed:12654995};
DE Short=S.StySPI {ECO:0000303|PubMed:12654995};
DE AltName: Full=Type-1 restriction enzyme StySPI specificity subunit;
GN Name=hsdS {ECO:0000303|PubMed:3025838};
OS Salmonella potsdam.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Salmonella.
OX NCBI_TaxID=597;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, AND DOMAIN.
RX PubMed=3025838; DOI=10.1073/pnas.83.24.9368;
RA Fuller-Pace F.V., Murray N.E.;
RT "Two DNA recognition domains of the specificity polypeptides of a family of
RT type I restriction enzymes.";
RL Proc. Natl. Acad. Sci. U.S.A. 83:9368-9372(1986).
RN [2]
RP DOMAIN.
RX PubMed=2838725; DOI=10.1111/j.1365-2958.1987.tb00521.x;
RA Gann A.A.F., Campbell A.J.B., Collins J.F., Coulson A.F.W., Murray N.E.;
RT "Reassortment of DNA recognition domains and the evolution of new
RT specificities.";
RL Mol. Microbiol. 1:13-22(1987).
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: The specificity (S) subunit of a type I restriction enzyme;
CC this subunit dictates DNA sequence specificity. The M and S subunits
CC together form a methyltransferase (MTase) that methylates A-2 on the
CC top strand and A-3 on the bottom strand of the sequence 5'-AACN(6)GTRC-
CC 3'. In the presence of the R subunit the complex can also act as an
CC endonuclease, binding to the same target sequence but cutting the DNA
CC some distance from this site. Whether the DNA is cut or modified
CC depends on the methylation state of the target sequence. When the
CC target site is unmodified, the DNA is cut. When the target site is
CC hemimethylated, the complex acts as a maintenance MTase modifying the
CC DNA so that both strands become methylated (PubMed:3025838,
CC PubMed:12654995). After locating a non-methylated recognition site, the
CC enzyme complex serves as a molecular motor that translocates DNA in an
CC ATP-dependent manner until a collision occurs that triggers cleavage
CC (By similarity). {ECO:0000250|UniProtKB:P05719,
CC ECO:0000269|PubMed:3025838, ECO:0000303|PubMed:12654995}.
CC -!- SUBUNIT: The type I restriction/modification system is composed of
CC three polypeptides R, M and S; the restriction enzyme has stoichiometry
CC R(2)M(2)S(1) while the methyltransferase is M(2)S(1).
CC {ECO:0000250|UniProtKB:P05719}.
CC -!- DOMAIN: Contains two DNA recognition domains, each specifying
CC recognition of one of the two defined components of the target sequence
CC (PubMed:3025838). The recognition domains can be exchanged between
CC different S proteins, generating enzymes that have new sequence
CC specificities (PubMed:2838725). {ECO:0000269|PubMed:2838725,
CC ECO:0000269|PubMed:3025838}.
CC -!- MISCELLANEOUS: Type I restriction and modification enzymes are complex,
CC multifunctional systems which require ATP, S-adenosyl methionine and
CC Mg(2+) as cofactors and, in addition to their endonucleolytic and
CC methylase activities, are potent DNA-dependent ATPases.
CC {ECO:0000250|UniProtKB:P05719}.
CC -!- SIMILARITY: Belongs to the type-I restriction system S methylase
CC family. {ECO:0000305}.
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DR EMBL; M14984; AAA27145.1; -; Genomic_DNA.
DR AlphaFoldDB; P07990; -.
DR SMR; P07990; -.
DR REBASE; 3689; S.StySPI.
DR PRIDE; P07990; -.
DR PRO; PR:P07990; -.
DR GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR GO; GO:0009307; P:DNA restriction-modification system; IEA:UniProtKB-KW.
DR Gene3D; 3.90.220.20; -; 2.
DR InterPro; IPR000055; Restrct_endonuc_typeI_TRD.
DR InterPro; IPR044946; Restrct_endonuc_typeI_TRD_sf.
DR Pfam; PF01420; Methylase_S; 2.
PE 3: Inferred from homology;
KW DNA-binding; Restriction system.
FT CHAIN 1..463
FT /note="Type I restriction enzyme StySPI specificity
FT subunit"
FT /id="PRO_0000198038"
SQ SEQUENCE 463 AA; 51190 MW; 1C42A1717F1E85CF CRC64;
MNRGKLPEGW ATAPVSTVTT LIRGVTYKKE QALNYLQDDY LPIIRANNIQ NGKFDTTDLV
FVPKNLVKES QKISPEDIVI AMSSGSKSVV GKSAHQRLPF ECSFGAFCGA LRPEKFISPN
YIAHFTKSSF YRNKISSLSA GANINNIKPA SFDLINIPIP SLAEQKIIAE KLDTLLAQVD
STKARLEQIP QILKRFRQAV LAAAVSGTLT TALRNSHSLI GWHSTNLGAL IVDSCNGLAK
RQGLNGNEIT ILRLADFKDA QRIIGNERKI KLDSKEENKY SLENDDILVI RVNGSADLAG
RFIEYKSNGD IEGFCDHFIR LRLDSNKIMS RFLTYIANEG EGRFYLRNSL STSAGQNTIN
QTSIKGLSFL LPPLKEQAEI VRRVEQLFAY ADTIEKQVNN ALTRVNSLTQ SILAKAFRGE
LTAQWRAENP DLISGKNSAA ALLEKIKAER AVSGGKKTSR KKA
