T1SB_ECOLX
ID T1SB_ECOLX Reviewed; 474 AA.
AC P06990;
DT 01-APR-1988, integrated into UniProtKB/Swiss-Prot.
DT 01-APR-1988, sequence version 1.
DT 25-MAY-2022, entry version 101.
DE RecName: Full=Type I restriction enzyme EcoBI specificity subunit {ECO:0000305};
DE Short=S protein;
DE AltName: Full=Type I specificity subunit S.EcoBI {ECO:0000303|PubMed:12654995};
DE Short=S.EcoBI {ECO:0000303|PubMed:12654995};
DE AltName: Full=Type-1 restriction enzyme EcoBI specificity subunit;
GN Name=hsdS {ECO:0000303|PubMed:6304321}; Synonyms=hss;
OS Escherichia coli.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Escherichia.
OX NCBI_TaxID=562;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=B / 629;
RX PubMed=6304321; DOI=10.1016/s0022-2836(83)80047-3;
RA Gough J.A., Murray N.E.;
RT "Sequence diversity among related genes for recognition of specific targets
RT in DNA molecules.";
RL J. Mol. Biol. 166:1-19(1983).
RN [2]
RP FUNCTION, AND SUBUNIT.
RC STRAIN=B;
RX PubMed=4568607; DOI=10.1016/s0021-9258(19)44780-7;
RA Eskin B., Linn S.;
RT "The deoxyribonucleic acid modification and restriction enzymes of
RT Escherichia coli B. II. Purification, subunit structure, and catalytic
RT properties of the restriction endonuclease.";
RL J. Biol. Chem. 247:6183-6191(1972).
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-3 on the
CC top strand and A-4 on the bottom strand of the sequence 5'-TGAN(8)TGCT-
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:4568607,
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:4568607, ECO:0000303|PubMed:12654995}.
CC -!- SUBUNIT: The type I restriction/modification system is composed of
CC three polypeptides R, M and S (PubMed:4568607). The restriction enzyme
CC has stoichiometry R(2)M(2)S(1) while the methyltransferase is M(2)S(1)
CC (By similarity). {ECO:0000250|UniProtKB:P05719,
CC ECO:0000269|PubMed:4568607}.
CC -!- DOMAIN: Contains two DNA recognition domains, each specifying
CC recognition of one of the two defined components of the target
CC sequence. {ECO:0000250|UniProtKB:P05719}.
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; V00286; CAA23552.1; -; Genomic_DNA.
DR RefSeq; WP_000009567.1; NZ_WTSN01000071.1.
DR AlphaFoldDB; P06990; -.
DR SMR; P06990; -.
DR REBASE; 191897; S.Apa1447ORF2439P.
DR REBASE; 246645; S.Mmy2708ORF27P.
DR REBASE; 3639; S.EcoBI.
DR PRO; PR:P06990; -.
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 1: Evidence at protein level;
KW DNA-binding; Restriction system.
FT CHAIN 1..474
FT /note="Type I restriction enzyme EcoBI specificity subunit"
FT /id="PRO_0000198032"
SQ SEQUENCE 474 AA; 53513 MW; 57183DE33E3B284E CRC64;
MSFNSTSKEL IEQNINGLLS IHDSWLRISM DSVANITNGF AFKSSEFNNR KDGVPLIRIR
DVLKGNTSTY YSGQIPEGYW VYPEDLIVGM DGDFNATIWC SEPALLNQRV CKIEVQEDKY
NKRFFYHALP GYLSAINANT SSVTVKHLSS RTLQDTLLPL PPLAEQKIIA EKLDTLLAQV
DSTKARLEQI PQILKRFRQA VLAAAVTGRL TKEDKDFITK KVELDNYKIL IPEDWSETIL
NNIINTQRPL CYGVVQPGDD IKDGIELIRV CDINDGEVDL NHLRKISKEI DLQYKRSKVR
KNDILVTIVG AIGRIGIVRE DINVNIARAV ARISPEYKII VPMFLHIWLS SPVMQTWLVQ
SSKEVARKTL NLKDLKNAFV PLPSIEEQHE IVRRVEQLFA YADSIEKQVN NALARVNNLT
QSILAKAFRG ELTAQWRAEN PDLISGENSA AALLEKIKAE RAASGGKKAS RKKF
