LTRA_LACLC
ID LTRA_LACLC Reviewed; 599 AA.
AC P0A3U0; Q57005; Q9FB65;
DT 15-MAR-2005, integrated into UniProtKB/Swiss-Prot.
DT 15-MAR-2005, sequence version 1.
DT 03-AUG-2022, entry version 63.
DE RecName: Full=Group II intron-encoded protein LtrA;
DE Includes:
DE RecName: Full=Reverse-transcriptase;
DE EC=2.7.7.49;
DE Includes:
DE RecName: Full=RNA maturase;
DE EC=3.1.-.-;
DE Includes:
DE RecName: Full=DNA endonuclease;
DE EC=3.1.-.-;
GN Name=ltrA; Synonyms=matR;
OS Lactococcus lactis subsp. cremoris (Streptococcus cremoris).
OG Plasmid pRS01, and Plasmid pAH82.
OC Bacteria; Firmicutes; Bacilli; Lactobacillales; Streptococcaceae;
OC Lactococcus.
OX NCBI_TaxID=1359;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=NCDO 763 / ML3; PLASMID=pRS01;
RX PubMed=8655550; DOI=10.1128/jb.178.12.3531-3538.1996;
RA Mills D.A., McKay L.L., Dunny G.M.;
RT "Splicing of a group II intron involved in the conjugative transfer of
RT pRS01 in Lactococci.";
RL J. Bacteriol. 178:3531-3538(1996).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC PLASMID=pAH82;
RX PubMed=11157264; DOI=10.1128/aem.67.2.929-937.2001;
RA O'Sullivan D., Ross R.P., Twomey D.P., Fitzgerald G.F., Hill C., Coffey A.;
RT "Naturally occurring lactococcal plasmid pAH90 links bacteriophage
RT resistance and mobility functions to a food-grade selectable marker.";
RL Appl. Environ. Microbiol. 67:929-937(2001).
RN [3]
RP CHARACTERIZATION.
RX PubMed=10488339; DOI=10.1016/s1097-2765(00)80371-8;
RA Wank H., SanFilippo J., Singh R.N., Matsuura M., Lambowitz A.M.;
RT "A reverse transcriptase/maturase promotes splicing by binding at its own
RT coding segment in a group II intron RNA.";
RL Mol. Cell 4:239-250(1999).
RN [4]
RP CHARACTERIZATION, AND MUTAGENESIS OF 308-ASP-ASP-309.
RX PubMed=9353259; DOI=10.1101/gad.11.21.2910;
RA Matsuura M., Saldanha R., Ma H., Wank H., Yang J., Mohr G., Cavanagh S.,
RA Dunny G.M., Belfort M., Lambowitz A.M.;
RT "A bacterial group II intron encoding reverse transcriptase, maturase, and
RT DNA endonuclease activities: biochemical demonstration of maturase activity
RT and insertion of new genetic information within the intron.";
RL Genes Dev. 11:2910-2924(1997).
RN [5]
RP CHARACTERIZATION.
RX PubMed=10413481; DOI=10.1021/bi982799l;
RA Saldanha R., Chen B., Wank H., Matsuura M., Edwards J., Lambowitz A.M.;
RT "RNA and protein catalysis in group II intron splicing and mobility
RT reactions using purified components.";
RL Biochemistry 38:9069-9083(1999).
RN [6]
RP INTRON RETARGETING.
RC STRAIN=NCDO 763 / ML3; PLASMID=pRS01;
RX PubMed=11731786; DOI=10.1038/nbt1201-1162;
RA Karberg M., Guo H., Zhong J., Coon R., Perutka J., Lambowitz A.M.;
RT "Group II introns as controllable gene targeting vectors for genetic
RT manipulation of bacteria.";
RL Nat. Biotechnol. 19:1162-1167(2001).
CC -!- FUNCTION: Multifunctional protein that promotes group II intron
CC splicing and mobility by acting both on RNA and DNA. It has three
CC activities: reverse transcriptase (RT) for intron duplication, maturase
CC to promote splicing, and DNA endonuclease for site-specific cleavage of
CC recipient alleles. The intron-encoded protein promotes splicing by
CC facilitating the formation of the catalytically active structure of the
CC intron RNA. After splicing, the protein remains bound to the excised
CC intron lariat RNA, forming ribonucleoprotein particles, and cleaving
CC the antisense strand of the recipient DNA in the 3' exon. After DNA
CC cleavage, retrohoming occurs by a target DNA-primed reverse
CC transcription of the intron RNA that had reverse spliced into the sense
CC strand of the recipient DNA. It also contributes to the recognition of
CC the DNA target site and acts as a repressor of its own translation.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) =
CC diphosphate + DNA(n+1); Xref=Rhea:RHEA:22508, Rhea:RHEA-COMP:17339,
CC Rhea:RHEA-COMP:17340, ChEBI:CHEBI:33019, ChEBI:CHEBI:61560,
CC ChEBI:CHEBI:173112; EC=2.7.7.49; Evidence={ECO:0000255|PROSITE-
CC ProRule:PRU00405};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC -!- SUBUNIT: Homodimer. {ECO:0000305}.
CC -!- BIOTECHNOLOGY: Mobile group II introns can be retargeted and used for
CC highly specific chromosomal gene disruption in bacteria. Could be
CC useful for genetic engineering and functional genomics in a wide
CC variety of bacteria.
CC -!- MISCELLANEOUS: The correct folding of LtrA seems to be facilitated by
CC binding to the unspliced precursor or intron RNA. RNA would serve in
CC part as a chaperone that promotes folding of the protein into an active
CC conformation. Purified protein lacks endonuclease activity unless
CC complexed with intron lariat RNA. It may preferentially function in cis
CC by binding to the intron RNA from which it was translated.
CC -!- SIMILARITY: In the N-terminal section; belongs to the bacterial reverse
CC transcriptase family. {ECO:0000305}.
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DR EMBL; U50902; AAB06503.1; -; Genomic_DNA.
DR EMBL; AF243383; AAF98310.1; -; Genomic_DNA.
DR RefSeq; WP_011835237.1; NZ_LITG01000148.1.
DR PDB; 5G2X; EM; 3.80 A; C=1-599.
DR PDB; 7D0F; EM; 5.00 A; C=1-599.
DR PDB; 7D0G; EM; 5.00 A; C=1-599.
DR PDB; 7D1A; EM; 3.80 A; C=1-599.
DR PDBsum; 5G2X; -.
DR PDBsum; 7D0F; -.
DR PDBsum; 7D0G; -.
DR PDBsum; 7D1A; -.
DR AlphaFoldDB; P0A3U0; -.
DR SMR; P0A3U0; -.
DR OMA; YNYYCLA; -.
DR GO; GO:0004519; F:endonuclease activity; IEA:UniProtKB-KW.
DR GO; GO:0003964; F:RNA-directed DNA polymerase activity; IEA:UniProtKB-KW.
DR GO; GO:0006314; P:intron homing; IEA:UniProtKB-KW.
DR GO; GO:0006397; P:mRNA processing; IEA:InterPro.
DR InterPro; IPR043502; DNA/RNA_pol_sf.
DR InterPro; IPR024937; Domain_X.
DR InterPro; IPR000477; RT_dom.
DR Pfam; PF01348; Intron_maturas2; 1.
DR Pfam; PF00078; RVT_1; 1.
DR SUPFAM; SSF56672; SSF56672; 1.
DR PROSITE; PS50878; RT_POL; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Endonuclease; Hydrolase; Intron homing; Magnesium;
KW Multifunctional enzyme; Nuclease; Nucleotidyltransferase; Plasmid;
KW RNA-directed DNA polymerase; Transferase.
FT CHAIN 1..599
FT /note="Group II intron-encoded protein LtrA"
FT /id="PRO_0000084512"
FT DOMAIN 70..361
FT /note="Reverse transcriptase"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00405"
FT REGION 381..549
FT /note="Intron maturase type-2"
FT MUTAGEN 308..309
FT /note="DD->AA: Loss of RT function."
FT /evidence="ECO:0000269|PubMed:9353259"
SQ SEQUENCE 599 AA; 70163 MW; 52A286BD5F504589 CRC64;
MKPTMAILER ISKNSQENID EVFTRLYRYL LRPDIYYVAY QNLYSNKGAS TKGILDDTAD
GFSEEKIKKI IQSLKDGTYY PQPVRRMYIA KKNSKKMRPL GIPTFTDKLI QEAVRIILES
IYEPVFEDVS HGFRPQRSCH TALKTIKREF GGARWFVEGD IKGCFDNIDH VTLIGLINLK
IKDMKMSQLI YKFLKAGYLE NWQYHKTYSG TPQGGILSPL LANIYLHELD KFVLQLKMKF
DRESPERITP EYRELHNEIK RISHRLKKLE GEEKAKVLLE YQEKRKRLPT LPCTSQTNKV
LKYVRYADDF IISVKGSKED CQWIKEQLKL FIHNKLKMEL SEEKTLITHS SQPARFLGYD
IRVRRSGTIK RSGKVKKRTL NGSVELLIPL QDKIRQFIFD KKIAIQKKDS SWFPVHRKYL
IRSTDLEIIT IYNSELRGIC NYYGLASNFN QLNYFAYLME YSCLKTIASK HKGTLSKTIS
MFKDGSGSWG IPYEIKQGKQ RRYFANFSEC KSPYQFTDEI SQAPVLYGYA RNTLENRLKA
KCCELCGTSD ENTSYEIHHV NKVKNLKGKE KWEMAMIAKQ RKTLVVCFHC HRHVIHKHK
