Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

Intron-encoded DNA endonuclease aI4

Gene

AI4

Organism
Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
Status
Reviewed-Annotation score: -Experimental evidence at protein leveli

Functioni

Mitochondrial DNA endonuclease involved in intron homing. It introduces a specific double-strand break at the junction of the two exons a4-a5 of the COX1 gene and thus mediates the insertion of an intron, containing its own coding sequence (group I intron), into an intronless gene. Recognizes with limited specificity and cleaves the sequence 5'-TTTGGTCACCCTGAAGTA-3'. The protein may acquire mRNA maturase activity, like the closely related bI4, through a single amino acid substitution Glu-362 to Lys or when present together with a mutant form of the imported mitochondrial leucyl-tRNA synthetase NAM2.5 Publications

Miscellaneous

Residues 299 to 556 are sufficient for endonuclease and intron homing activity.

Cofactori

Mg2+1 Publication, Mn2+1 Publication

GO - Molecular functioni

  • cytochrome-c oxidase activity Source: InterPro
  • endonuclease activity Source: SGD
  • heme binding Source: InterPro

GO - Biological processi

  • aerobic respiration Source: GO_Central
  • electron transport coupled proton transport Source: GO_Central
  • intron homing Source: SGD
  • mitochondrial electron transport, cytochrome c to oxygen Source: GO_Central
  • mRNA processing Source: UniProtKB-KW
  • RNA splicing Source: SGD

Keywordsi

Molecular functionEndonuclease, Hydrolase, Nuclease
Biological processIntron homing, mRNA processing, mRNA splicing

Enzyme and pathway databases

BioCyciYEAST:G3O-34375-MONOMER

Protein family/group databases

REBASEi2616 I-SceII

Names & Taxonomyi

Protein namesi
Recommended name:
Intron-encoded DNA endonuclease aI4
Alternative name(s):
DNA endonuclease I-SceII
Cleaved into the following 2 chains:
Alternative name(s):
Intron-encoded endonuclease I-SceII
Gene namesi
Name:AI4
Synonyms:ENS2, I-SCEII
Ordered Locus Names:Q0065
Encoded oniMitochondrion
OrganismiSaccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
Taxonomic identifieri559292 [NCBI]
Taxonomic lineageiEukaryotaFungiDikaryaAscomycotaSaccharomycotinaSaccharomycetesSaccharomycetalesSaccharomycetaceaeSaccharomyces
Proteomesi
  • UP000002311 Componenti: Mitochondrion

Organism-specific databases

EuPathDBiFungiDB:Q0065
SGDiS000007264 AI4

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cell wall Cytoskeleton Vacuole Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Keywords - Cellular componenti

Mitochondrion

Pathology & Biotechi

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi362E → K: Confers mRNA maturase activity. 1 Publication1

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_0000013490? – 556DNA endonuclease aI4
ChainiPRO_00000134891 – ?Truncated non-functional cytochrome oxidase 1

Post-translational modificationi

The mature protein may arise from proteolytic cleavage of an in-frame translation of COX1 exons 1 to 4 plus intron 4, containing the aI4 open reading frame. Cleavage would take place close to the Met-299 resulting in an active endonuclease of about 30 kDa.3 Publications

Proteomic databases

MaxQBiP03878
PaxDbiP03878
PRIDEiP03878

Interactioni

Subunit structurei

Homodimer.Curated

Protein-protein interaction databases

BioGridi34788, 2 interactors
STRINGi4932.Q0065

Structurei

3D structure databases

ProteinModelPortaliP03878
SMRiP03878
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni1 – 240COX1 exons 1 to 4 encodedAdd BLAST240
Regioni241 – 556COX1 intron 4 encodedAdd BLAST316

Sequence similaritiesi

In the C-terminal section; belongs to the LAGLIDADG endonuclease family.Curated
In the N-terminal section; belongs to the heme-copper respiratory oxidase family.Curated

Phylogenomic databases

GeneTreeiENSGT00840000130858
InParanoidiP03878
OrthoDBiEOG092C2KU4

Family and domain databases

Gene3Di1.20.210.10, 1 hit
3.10.28.10, 2 hits
InterProiView protein in InterPro
IPR023616 Cyt_c_oxase-like_su1_dom
IPR036927 Cyt_c_oxase-like_su1_sf
IPR000883 Cyt_C_Oxase_1
IPR027434 Homing_endonucl
IPR004860 LAGLIDADG_2
PANTHERiPTHR10422 PTHR10422, 1 hit
PfamiView protein in Pfam
PF00115 COX1, 1 hit
PF00961 LAGLIDADG_1, 2 hits
PRINTSiPR01165 CYCOXIDASEI
SUPFAMiSSF55608 SSF55608, 2 hits
SSF81442 SSF81442, 1 hit
PROSITEiView protein in PROSITE
PS50855 COX1, 1 hit

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P03878-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MVQRWLYSTN AKDIAVLYFM LAIFSGMAGT AMSLIIRLEL AAPGSQYLHG
60 70 80 90 100
NSQLFNVLVV GHAVLMIFFL VMPALIGGFG NYLLPLMIGA TDTAFPRINN
110 120 130 140 150
IAFWVLPMGL VCLVTSTLVE SGAGTGWTVY PPLSSIQAHS GPSVDLAIFA
160 170 180 190 200
LHLTSISSLL GAINFIVTTL NMRTNGMTMH KLPLFVWSIF ITAFLLLLSL
210 220 230 240 250
PVLSAGITML LLDRNFNTSF FEVSGGGDPI LYEHLFWFFG QTVATIIMLM
260 270 280 290 300
MYNDMHFSKC WKLLKKWITN IMSTLFKALF VKMFMSYNNQ QDKMMNNTML
310 320 330 340 350
KKDNIKRSSE TTRKMLNNSM NKKFNQWLAG LIDGDGYFGI VSKKYVSLEI
360 370 380 390 400
TVALEDEMAL KEIQNKFGGS IKLRSGVKAI RYRLTNKTGM IKLINAVNGN
410 420 430 440 450
IRNTKRLVQF NKVCILLGID FIYPIKLTKD NSWFVGFFDA DGTINYSFKN
460 470 480 490 500
NHPQLTISVT NKYLQDVQEY KNILGGNIYF DKSQNGYYKW SIQSKDMVLN
510 520 530 540 550
FINDYIKMNP SRTTKMNKLY LSKEFYNLKE LKAYNKSSDS MQYKAWLNFE

NKWKNK
Length:556
Mass (Da):63,311
Last modified:July 19, 2004 - v3
Checksum:i4F1D968F23DABA7A
GO

Sequence cautioni

The sequence CAA24064 differs from that shown. Reason: Erroneous gene model prediction. COX1 was not predicted to be expressed alternatively as a fusion with intron 4.Curated
The sequence CAA24070 differs from that shown. Reason: Erroneous gene model prediction. COX1 was not predicted to be expressed alternatively as a fusion with intron 4.Curated

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti57Missing in CAA24070 (PubMed:6254986).Curated1
Sequence conflicti69F → CT in CAA24070 (PubMed:6254986).Curated1
Sequence conflicti224S → A in CAA24070 (PubMed:6254986).Curated1
Sequence conflicti315M → I in AAB21126 (PubMed:1310149).Curated1
Sequence conflicti320M → I in AAB21126 (PubMed:1310149).Curated1

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural varianti457 – 458IS → KT in strain: D273-10B. 2

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
V00694 Genomic DNA Translation: CAA24070.1 Sequence problems.
V00694 Genomic DNA Translation: CAA24064.1 Sequence problems.
KP263414 Genomic DNA Translation: AIZ98883.1
V00703 Genomic DNA Translation: CAA24076.1
S76641 Genomic DNA Translation: AAB21126.1
PIRiS26762
S78649 QXBY34
RefSeqiNP_009307.2, NC_001224.1

Genome annotation databases

EnsemblFungiiQ0065; Q0065; Q0065
GeneIDi854596
KEGGisce:Q0065

Similar proteinsi

Entry informationi

Entry nameiSCE2_YEAST
AccessioniPrimary (citable) accession number: P03878
Secondary accession number(s): A0A0A7P354
, Q02339, Q35798, Q9ZZX2
Entry historyiIntegrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: July 19, 2004
Last modified: May 23, 2018
This is version 146 of the entry and version 3 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programFungal Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. Protein nomenclature information
    List of publications dealing with protein nomenclature and links to specialized websites

We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.

Do not show this banner again
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health