T1SA_ECOLX
ID T1SA_ECOLX Reviewed; 589 AA.
AC P19704;
DT 01-FEB-1991, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1995, sequence version 2.
DT 25-MAY-2022, entry version 81.
DE RecName: Full=Type I restriction enzyme EcoAI specificity subunit {ECO:0000303|PubMed:2642743};
DE Short=S protein {ECO:0000303|PubMed:2642743};
DE AltName: Full=Type I specificity subunit S.EcoAI {ECO:0000303|PubMed:12654995};
DE Short=S.EcoAI {ECO:0000303|PubMed:12654995};
DE AltName: Full=Type-1 restriction enzyme EcoAI specificity subunit;
GN Name=hsdS {ECO:0000303|PubMed:2642743}; Synonyms=hss;
OS Escherichia coli.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Escherichia.
OX NCBI_TaxID=562;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, AND DOMAIN.
RC STRAIN=15T;
RX PubMed=2642743; DOI=10.1016/0092-8674(89)90988-4;
RA Cowan G.M., Gann A.A.F., Murray N.E.;
RT "Conservation of complex DNA recognition domains between families of
RT restriction enzymes.";
RL Cell 56:103-109(1989).
RN [2]
RP FUNCTION, RECOGNITION SEQUENCE, AND SUBUNIT.
RC STRAIN=15T;
RX PubMed=6325176; DOI=10.1002/j.1460-2075.1984.tb01850.x;
RA Suri B., Shepherd J.C., Bickle T.A.;
RT "The EcoA restriction and modification system of Escherichia coli 15T-:
RT enzyme structure and DNA recognition sequence.";
RL EMBO J. 3:575-579(1984).
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'-GAGN(7)GTCA-
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:2642743,
CC PubMed:6325176, PubMed:12654995). After locating a non-methylated
CC recognition site, the enzyme complex serves as a molecular motor that
CC translocates DNA in an ATP-dependent manner until a collision occurs
CC that triggers cleavage (By similarity). {ECO:0000250|UniProtKB:P05719,
CC ECO:0000269|PubMed:2642743, ECO:0000269|PubMed:6325176,
CC ECO:0000303|PubMed:12654995}.
CC -!- SUBUNIT: The type I restriction/modification system is composed of
CC three polypeptides R, M and S (PubMed:6325176). 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:6325176}.
CC -!- DOMAIN: Contains two DNA recognition domains, each specifying
CC recognition of one of the two defined components of the target
CC sequence. {ECO:0000269|PubMed:2642743}.
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}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; J03150; AAA23987.1; -; Genomic_DNA.
DR PIR; A32343; NDECAS.
DR RefSeq; WP_029487515.1; NZ_LVLZ01000080.1.
DR AlphaFoldDB; P19704; -.
DR SMR; P19704; -.
DR REBASE; 205031; S1.Bve72ORF2738P.
DR REBASE; 233081; S.Sen4024ORF3807P.
DR REBASE; 3638; S.EcoAI.
DR eggNOG; COG0732; Bacteria.
DR PRO; PR:P19704; -.
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..589
FT /note="Type I restriction enzyme EcoAI specificity subunit"
FT /id="PRO_0000198031"
SQ SEQUENCE 589 AA; 66693 MW; EE96659058ED9C18 CRC64;
MSVEKLIVDH METWTSALQT RSTAGRGSSG KIDLYGIKKL RELILELAVR GKLVPQDPND
EPASELLKRI AAEKAELVKQ GKIKKQKPLP EISEEEKPFE LPDGWEWTTL TRIAEINPKI
DVSDDEQEIS FIPMPLISTK FDGSHEFEIK KWKDVKKGYT HFANGDIAIA KITPCFENSK
AAIFSGLKNG IGVGTTELHV ARPFSDIINR KYLLLNFKSP NFLKSGESQM TGSAGQKRVP
RFFFENNPIP FPPLQEQERI IIRFTQLMSL CDQLEQQSLT SLDAHQQLVE TLLGTLTDSQ
NVEELAENWA RISEHFDTLF TTEASVDALK QTILQLAVMG KLVPQDPNDE PASELLKRIA
QEKAQLVKEG KIKKQKPLPP ISDEEKPFEL PEGWEWCRLG SIYNFLNGYA FKSEWFTSVG
LRLLRNANIA HGVTNWKDVV HIPNDMISDF ENYILSENDI VISLDRPIIN TGLKYAIISK
SDLPCLLLQR VAKFKNYANT VSNSFLTIWL QSYFFINSID PGRSNGVPHI STKQLEMTLF
PLLPQSEQDR IISKMDELIQ TCNKLKYIIK TAKQTQLHLA DALTDAAIN
