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UniProtKB/Swiss-Prot entry P0A3U0


[Entry info] [Name and origin] [References] [Comments] [Cross-references] [Keywords] [Features] [Sequence] [Tools]

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Entry information
Entry name LTRA_LACLC
Primary accession number P0A3U0
Secondary accession numbers Q57005 Q9FB65
Integrated into Swiss-Prot on March 15, 2005
Sequence was last modified on March 15, 2005 (Sequence version 1)
Annotations were last modified on    June 16, 2009 (Entry version 20)
Name and origin of the protein
Protein name Group II intron-encoded protein ltrA
Synonyms None
Includes Reverse-transcriptase
     (EC 2.7.7.49)
RNA maturase
     (EC 3.1.-.-)
DNA endonuclease
     (EC 3.1.-.-)
Gene name
Name: ltrA
Synonyms: matR
From
Lactococcus lactis subsp. cremoris (Streptococcus cremoris) [TaxID: 1359] 
Encoded on Plasmid pRS01; Plasmid pAH82.
Taxonomy Bacteria; Firmicutes; Lactobacillales; Streptococcaceae; Lactococcus.
Protein existence 1: Evidence at protein level;
References
[1]
NUCLEOTIDE SEQUENCE [GENOMIC DNA].
PLASMID=pRS01;
STRAIN=NCDO 763 / ML3;
PubMed=8655550 [NCBI, ExPASy, EBI, Israel, Japan]
Mills D.A., McKay L.L., Dunny G.M.;
"Splicing of a group II intron involved in the conjugative transfer of pRS01 in Lactococci.";
J. Bacteriol. 178:3531-3538(1996).
[2]
NUCLEOTIDE SEQUENCE [GENOMIC DNA].
PLASMID=pAH82;
DOI=10.1128/AEM.67.2.929-937.2001; PubMed=11157264 [NCBI, ExPASy, EBI, Israel, Japan]
O'Sullivan D., Ross R.P., Twomey D.P., Fitzgerald G.F., Hill C., Coffey A.;
"Naturally occurring lactococcal plasmid pAH90 links bacteriophage resistance and mobility functions to a food-grade selectable marker.";
Appl. Environ. Microbiol. 67:929-937(2001).
[3]
CHARACTERIZATION.
DOI=10.1016/S1097-2765(00)80371-8; PubMed=10488339 [NCBI, ExPASy, EBI, Israel, Japan]
Wank H., SanFilippo J., Singh R.N., Matsuura M., Lambowitz A.M.;
"A reverse transcriptase/maturase promotes splicing by binding at its own coding segment in a group II intron RNA.";
Mol. Cell 4:239-250(1999).
[4]
CHARACTERIZATION, AND MUTAGENESIS OF 308-ASP-ASP-309.
PubMed=9353259 [NCBI, ExPASy, EBI, Israel, Japan]
Matsuura M., Saldanha R., Ma H., Wank H., Yang J., Mohr G., Cavanagh S., Dunny G.M., Belfort M., Lambowitz A.M.;
"A bacterial group II intron encoding reverse transcriptase, maturase, and DNA endonuclease activities: biochemical demonstration of maturase activity and insertion of new genetic information within the intron.";
Genes Dev. 11:2910-2924(1997).
[5]
CHARACTERIZATION.
DOI=10.1021/bi982799l; PubMed=10413481 [NCBI, ExPASy, EBI, Israel, Japan]
Saldanha R., Chen B., Wank H., Matsuura M., Edwards J., Lambowitz A.M.;
"RNA and protein catalysis in group II intron splicing and mobility reactions using purified components.";
Biochemistry 38:9069-9083(1999).
[6]
INTRON RETARGETING.
PLASMID=pRS01;
STRAIN=NCDO 763 / ML3;
DOI=10.1038/nbt1201-1162; PubMed=11731786 [NCBI, ExPASy, EBI, Israel, Japan]
Karberg M., Guo H., Zhong J., Coon R., Perutka J., Lambowitz A.M.;
"Group II introns as controllable gene targeting vectors for genetic manipulation of bacteria.";
Nat. Biotechnol. 19:1162-1167(2001).
Comments
  • FUNCTION: Multifunctional protein that promotes group II intron splicing and mobility by acting both on RNA and DNA. It has three activities: reverse transcriptase (RT) for intron duplication, maturase to promote splicing, and DNA endonuclease for site-specific cleavage of recipient alleles. The intron-encoded protein promotes splicing by facilitating the formation of the catalytically active structure of the intron RNA. After splicing, the protein remains bound to the excised intron lariat RNA, forming ribonucleoprotein particles, and cleaving the antisense strand of the recipient DNA in the 3' exon. After DNA cleavage, retrohoming occurs by a target DNA-primed reverse transcription of the intron RNA that had reverse spliced into the sense strand of the recipient DNA. It also contributes to the recognition of the DNA target site and acts as a repressor of its own translation.
  • CATALYTIC ACTIVITY: Deoxynucleoside triphosphate + DNA(n) = diphosphate + DNA(n+1).
  • COFACTOR: Magnesium.
  • SUBUNIT: Homodimer (Probable).
  • BIOTECHNOLOGY: Mobile group II introns can be retargeted and used for highly specific chromosomal gene disruption in bacteria. Could be useful for genetic engineering and functional genomics in a wide variety of bacteria.
  • MISCELLANEOUS: The correct folding of ltrA seems to be facilitated by binding to the unspliced precursor or intron RNA. RNA would serve in part as a chaperone that promotes folding of the protein into an active conformation. Purified protein lacks endonuclease activity unless complexed with intron lariat RNA. It may preferentially function in cis by binding to the intron RNA from which it was translated.
  • SIMILARITY: Contains 1 reverse transcriptase domain.
Copyright
Copyrighted by the UniProt Consortium, see http://www.uniprot.org/terms. Distributed under the Creative Commons Attribution-NoDerivs License.
Cross-references
Sequence databases
EMBL
U50902; AAB06503.1; -; Genomic_DNA.[EMBL / GenBank / DDBJ] [CoDingSequence]
AF243383; AAF98310.1; -; Genomic_DNA.[EMBL / GenBank / DDBJ] [CoDingSequence]
3D structure databases
ModBase P0A3U0.
Enzyme and pathway databases
BRENDA 2.7.7.49; 289716.
Ontologies
GO
GO:0004519; Molecular function: endonuclease activity (inferred from electronic annotation from UniProtKB-KW).
GO:0000287; Molecular function: magnesium ion binding (inferred from electronic annotation from UniProtKB-KW).
GO:0003723; Molecular function: RNA binding (inferred from electronic annotation from InterPro).
GO:0003964; Molecular function: RNA-directed DNA polymerase activity (inferred from electronic annotation from UniProtKB-KW).
GO:0006314; Biological process: intron homing (inferred from electronic annotation from UniProtKB-KW).
GO:0008380; Biological process: RNA splicing (inferred from electronic annotation from InterPro).
GO:0006278; Biological process: RNA-dependent DNA replication (inferred from electronic annotation from InterPro).
QuickGo view.
Family and domain databases
InterPro IPR000477; DNA_pol_RVTase.
IPR003615; HNH_nuc.
IPR000442; Intron_maturse2.
Graphical view of domain structure.
Pfam PF01348; Intron_maturas2; 1.
PF00078; RVT_1; 1.
Pfam graphical view of domain structure.
SMART SM00507; HNHc; 1.
SMART graphical view of domain structure.
PROSITE PS50878; RT_POL; 1.
PROSITE graphical view of domain structure (profiles).
Other
ProtoNet P0A3U0.
UniRef View cluster of proteins with at least 50% / 90% / 100% identity.
Keywords
Endonuclease; Hydrolase; Intron homing; Magnesium; Multifunctional enzyme; Nuclease; Nucleotidyltransferase; Plasmid; RNA-directed DNA polymerase; Transferase.
Features
SEVIEWER logo Feature table viewer FT aligner logo Feature aligner
KeyFrom   To Length Description FTId
CHAIN   1   599  599     Group II intron-encoded protein ltrA. PRO_0000084512
DOMAIN   70   361  292     Reverse transcriptase. 
REGION   381   549  169     Intron maturase type-2. 
MUTAGEN   308   309        DD->AA: Loss of RT function. 
Sequence information
Length: 599 AA [This is the length of the unprocessed precursor] Molecular weight: 70163 Da [This is the MW of the unprocessed precursor] CRC64: 52A286BD5F504589 [This is a checksum on the sequence]
        10         20         30         40         50         60 
MKPTMAILER ISKNSQENID EVFTRLYRYL LRPDIYYVAY QNLYSNKGAS TKGILDDTAD 

        70         80         90        100        110        120 
GFSEEKIKKI IQSLKDGTYY PQPVRRMYIA KKNSKKMRPL GIPTFTDKLI QEAVRIILES 

       130        140        150        160        170        180 
IYEPVFEDVS HGFRPQRSCH TALKTIKREF GGARWFVEGD IKGCFDNIDH VTLIGLINLK 

       190        200        210        220        230        240 
IKDMKMSQLI YKFLKAGYLE NWQYHKTYSG TPQGGILSPL LANIYLHELD KFVLQLKMKF 

       250        260        270        280        290        300 
DRESPERITP EYRELHNEIK RISHRLKKLE GEEKAKVLLE YQEKRKRLPT LPCTSQTNKV 

       310        320        330        340        350        360 
LKYVRYADDF IISVKGSKED CQWIKEQLKL FIHNKLKMEL SEEKTLITHS SQPARFLGYD 

       370        380        390        400        410        420 
IRVRRSGTIK RSGKVKKRTL NGSVELLIPL QDKIRQFIFD KKIAIQKKDS SWFPVHRKYL 

       430        440        450        460        470        480 
IRSTDLEIIT IYNSELRGIC NYYGLASNFN QLNYFAYLME YSCLKTIASK HKGTLSKTIS 

       490        500        510        520        530        540 
MFKDGSGSWG IPYEIKQGKQ RRYFANFSEC KSPYQFTDEI SQAPVLYGYA RNTLENRLKA 

       550        560        570        580        590 
KCCELCGTSD ENTSYEIHHV NKVKNLKGKE KWEMAMIAKQ RKTLVVCFHC HRHVIHKHK 

P0A3U0 in FASTA format

View entry in raw text format (no links)
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