MBI4_YEAST
ID MBI4_YEAST Reviewed; 638 AA.
AC P03879; A0A0A7NYH9; Q02324; Q9ZZW6;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 19-JUL-2004, sequence version 2.
DT 03-AUG-2022, entry version 151.
DE RecName: Full=Intron-encoded RNA maturase bI4;
DE AltName: Full=RNA maturase SCbI4;
DE Contains:
DE RecName: Full=Truncated, nonfunctional cytochrome b;
DE Contains:
DE RecName: Full=RNA maturase bI4;
DE EC=3.1.-.-;
DE Flags: Precursor;
GN Name=BI4; Synonyms=SCBI4; OrderedLocusNames=Q0120;
OS Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast).
OG Mitochondrion.
OC Eukaryota; Fungi; Dikarya; Ascomycota; Saccharomycotina; Saccharomycetes;
OC Saccharomycetales; Saccharomycetaceae; Saccharomyces.
OX NCBI_TaxID=559292;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=ATCC 24657 / D273-10B;
RX PubMed=6253454; DOI=10.1016/s0021-9258(18)43467-9;
RA Nobrega F.G., Tzagoloff A.;
RT "Assembly of the mitochondrial membrane system. DNA sequence and
RT organization of the cytochrome b gene in Saccharomyces cerevisiae D273-
RT 10B.";
RL J. Biol. Chem. 255:9828-9837(1980).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=ATCC 96604 / S288c / FY1679;
RX PubMed=9872396; DOI=10.1016/s0014-5793(98)01467-7;
RA Foury F., Roganti T., Lecrenier N., Purnelle B.;
RT "The complete sequence of the mitochondrial genome of Saccharomyces
RT cerevisiae.";
RL FEBS Lett. 440:325-331(1998).
RN [3]
RP GENOME REANNOTATION.
RC STRAIN=ATCC 96604 / S288c / FY1679;
RX PubMed=24374639; DOI=10.1534/g3.113.008995;
RA Engel S.R., Dietrich F.S., Fisk D.G., Binkley G., Balakrishnan R.,
RA Costanzo M.C., Dwight S.S., Hitz B.C., Karra K., Nash R.S., Weng S.,
RA Wong E.D., Lloyd P., Skrzypek M.S., Miyasato S.R., Simison M., Cherry J.M.;
RT "The reference genome sequence of Saccharomyces cerevisiae: Then and now.";
RL G3 (Bethesda) 4:389-398(2014).
RN [4]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 385-638.
RC STRAIN=ATCC 201238 / W303-1B;
RX PubMed=1310149; DOI=10.1128/mcb.12.2.696-705.1992;
RA Goguel V., Delahodde A., Jacq C.;
RT "Connections between RNA splicing and DNA intron mobility in yeast
RT mitochondria: RNA maturase and DNA endonuclease switching experiments.";
RL Mol. Cell. Biol. 12:696-705(1992).
RN [5]
RP FUNCTION, AND INTERACTION WITH NAM2.
RX PubMed=3284745; DOI=10.1002/j.1460-2075.1988.tb02835.x;
RA Herbert C.J., Labouesse M., Dujardin G., Slonimski P.P.;
RT "The NAM2 proteins from S. cerevisiae and S. douglasii are mitochondrial
RT leucyl-tRNA synthetases, and are involved in mRNA splicing.";
RL EMBO J. 7:473-483(1988).
RN [6]
RP FUNCTION, AND EXPRESSION AS COB FUSION PROTEIN.
RX PubMed=2560681; DOI=10.1007/bf00422109;
RA Goguel V., Perea J., Jacq C.;
RT "Synthesis and function of the mitochondrial intron -- encoded bI4 RNA
RT maturase from Saccharomyces cerevisiae. Effects of upstream frameshift
RT mutations.";
RL Curr. Genet. 16:241-246(1989).
RN [7]
RP FUNCTION, AND PROTEOLYTIC CLEAVAGE.
RX PubMed=8352597; DOI=10.1146/annurev.bi.62.070193.003103;
RA Lambowitz A.M., Belfort M.;
RT "Introns as mobile genetic elements.";
RL Annu. Rev. Biochem. 62:587-622(1993).
RN [8]
RP FUNCTION, AND INTERACTION WITH NAM2.
RX PubMed=11142386; DOI=10.1017/s1355838200001254;
RA Rho S.B., Martinis S.A.;
RT "The bI4 group I intron binds directly to both its protein splicing
RT partners, a tRNA synthetase and maturase, to facilitate RNA splicing
RT activity.";
RL RNA 6:1882-1894(2000).
CC -!- FUNCTION: Mitochondrial mRNA maturase required for splicing of intron 4
CC of the cytochrome b (COB) gene, containing its own coding sequence, and
CC intron 4 in COX1, coding for the related homing endonuclease aI4. In
CC vivo splicing requires in addition the imported mitochondrial leucyl-
CC tRNA synthetase NAM2. Both proteins seem to stimulate the intrinsic
CC ribozyme activity of intron bI4 through binding to and stabilizing
CC specific secondary and tertiary structure elements in the RNA.
CC {ECO:0000269|PubMed:11142386, ECO:0000269|PubMed:2560681,
CC ECO:0000269|PubMed:3284745, ECO:0000269|PubMed:8352597}.
CC -!- SUBUNIT: Forms a ternary complex with intron derived RNA and the
CC imported mitochondrial leucyl-tRNA synthetase NAM2. The proteins do not
CC interact directly with each other.
CC -!- SUBCELLULAR LOCATION: Mitochondrion.
CC -!- PTM: The mature protein may arise from proteolytic cleavage of an in-
CC frame translation of COB exons 1 to 4 plus intron 4, containing the bI4
CC open reading frame. Cleavage would take place close to the Met-385
CC resulting in an active maturase of about 30 kDa.
CC {ECO:0000269|PubMed:8352597}.
CC -!- MISCELLANEOUS: Residues 385 to 638 are sufficient for maturase
CC activity.
CC -!- SIMILARITY: In the C-terminal section; belongs to the LAGLIDADG
CC endonuclease family. {ECO:0000305}.
CC -!- SEQUENCE CAUTION:
CC Sequence=CAA24073.2; Type=Erroneous gene model prediction; Note=COB was not predicted to be expressed alternatively as a fusion with intron 4.; Evidence={ECO:0000305};
CC Sequence=CAB43023.1; Type=Erroneous gene model prediction; Note=COB was not predicted to be expressed alternatively as a fusion with intron 4.; Evidence={ECO:0000305};
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DR EMBL; V00696; CAB43023.1; ALT_SEQ; Genomic_DNA.
DR EMBL; V00696; CAA24073.2; ALT_SEQ; Genomic_DNA.
DR EMBL; KP263414; AIZ98891.1; -; Genomic_DNA.
DR EMBL; S76640; AAB21125.2; -; Genomic_DNA.
DR PIR; S78666; QQBY2M.
DR RefSeq; NP_009316.1; NC_001224.1.
DR AlphaFoldDB; P03879; -.
DR SMR; P03879; -.
DR BioGRID; 34778; 8.
DR ComplexPortal; CPX-1314; bI4 intron splicing factor complex.
DR IntAct; P03879; 1.
DR STRING; 4932.Q0120; -.
DR PaxDb; P03879; -.
DR PRIDE; P03879; -.
DR EnsemblFungi; Q0120_mRNA; Q0120; Q0120.
DR GeneID; 854582; -.
DR KEGG; sce:Q0120; -.
DR SGD; S000007273; BI4.
DR VEuPathDB; FungiDB:Q0120; -.
DR eggNOG; KOG4663; Eukaryota.
DR GeneTree; ENSGT00390000017948; -.
DR HOGENOM; CLU_429071_0_0_1; -.
DR InParanoid; P03879; -.
DR BioCyc; YEAST:G3O-34382-MON; -.
DR PRO; PR:P03879; -.
DR Proteomes; UP000002311; Mitochondrion.
DR RNAct; P03879; protein.
DR GO; GO:0005739; C:mitochondrion; IDA:SGD.
DR GO; GO:0004519; F:endonuclease activity; IEA:InterPro.
DR GO; GO:0003723; F:RNA binding; IDA:SGD.
DR GO; GO:0000372; P:Group I intron splicing; IDA:SGD.
DR GO; GO:0090615; P:mitochondrial mRNA processing; IMP:SGD.
DR GO; GO:0006397; P:mRNA processing; IDA:ComplexPortal.
DR CDD; cd00284; Cytochrome_b_N; 1.
DR Gene3D; 1.20.810.10; -; 1.
DR Gene3D; 3.10.28.10; -; 2.
DR InterPro; IPR005797; Cyt_b/b6_N.
DR InterPro; IPR027387; Cytb/b6-like_sf.
DR InterPro; IPR016174; Di-haem_cyt_TM.
DR InterPro; IPR027434; Homing_endonucl.
DR InterPro; IPR004860; LAGLIDADG_2.
DR Pfam; PF00033; Cytochrome_B; 1.
DR Pfam; PF00961; LAGLIDADG_1; 2.
DR SUPFAM; SSF55608; SSF55608; 2.
DR SUPFAM; SSF81342; SSF81342; 1.
DR PROSITE; PS51002; CYTB_NTER; 1.
PE 1: Evidence at protein level;
KW Hydrolase; Mitochondrion; mRNA processing; mRNA splicing;
KW Reference proteome.
FT CHAIN 1..?
FT /note="Truncated, nonfunctional cytochrome b"
FT /id="PRO_0000014020"
FT CHAIN ?..638
FT /note="RNA maturase bI4"
FT /id="PRO_0000014021"
FT REGION 1..253
FT /note="COB exons 1 to 4 encoded"
FT REGION 253..638
FT /note="COB intron 4 encoded"
FT CONFLICT 370
FT /note="K -> E (in Ref. 1; CAB43023)"
FT /evidence="ECO:0000305"
FT CONFLICT 390
FT /note="T -> L (in Ref. 4; AAB21125)"
FT /evidence="ECO:0000305"
FT CONFLICT 433
FT /note="E -> K (in Ref. 4; AAB21125)"
FT /evidence="ECO:0000305"
FT CONFLICT 459
FT /note="A -> T (in Ref. 1; CAB43023)"
FT /evidence="ECO:0000305"
FT CONFLICT 465
FT /note="Q -> K (in Ref. 4; AAB21125)"
FT /evidence="ECO:0000305"
FT CONFLICT 586
FT /note="T -> L (in Ref. 4; AAB21125)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 638 AA; 74580 MW; E0D89849FF75C858 CRC64;
MAFRKSNVYL SLVNSYIIDS PQPSSINYWW NMGSLLGLCL VIQIVTGIFM AMHYSSNIEL
AFSSVEHIMR DVHNGYILRY LHANGASFFF MVMFMHMAKG LYYGSYRSPR VTLWNVGVII
FILTIATAFL GYCCVYGQMS HWGATVITNL FSAIPFVGND IVSWLWGGFS VSNPTIQRFF
ALHYLVPFII AAMVIMHLMA LHIHGSSNPL GITGNLDRIP MHSYFIFKDL VTVFLFMLIL
ALFVFYSPNT LGQNMALLLI TYVINILCAV CWKSLFIKYQ WKIYNKTTYY FIIQNILNTK
QLNNFVLKFN WTKQYNKMNI VSDLFNPNRV KYYYKEDNQQ VTNMNSSNTH LTSNKKNLLV
DTSETTRTTK NKFNYLLNIF NMKKMNQIIT KRHYSIYKDS NIRFNQWLAG LIDGDGYFCI
TKNKYASCEI TVELKDEKML RQIQDKFGGS VKLRSGVKAI RYRLQNKEGM IKLINAVNGN
IRNSKRLVQF NKVCILLNID FKEPIKLTKD NAWFMGFFDA DGTINYYYSG KLKIRPQLTI
SVTNKYLHDV EYYREVFGGN IYFDKAKNGY FKWSINNKEL HNIFYTYNKS CPSKSNKGKR
LFLIDKFYYL YDLLAFKAPH NTALYKAWLK FNEKWNNN
