MBI2_YEAST
ID MBI2_YEAST Reviewed; 423 AA.
AC P03873; A0A0A7P383; Q9T2W1; Q9ZZW8;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 21-FEB-2006, sequence version 2.
DT 03-AUG-2022, entry version 168.
DE RecName: Full=Cytochrome b mRNA maturase bI2;
GN Name=BI2; OrderedLocusNames=Q0110;
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 [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 [2]
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 [3]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-143.
RC STRAIN=D273-10B/A21;
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 [4]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 20-423, VARIANTS THR-122 AND MET-324,
RP MUTAGENESIS OF VAL-364 AND ILE-393, AND FUNCTION.
RC STRAIN=ATCC 44821 / 777-3A;
RX PubMed=7004642; DOI=10.1016/0092-8674(80)90344-x;
RA Lazowska J., Jacq C., Slonimski P.P.;
RT "Sequence of introns and flanking exons in wild-type and box3 mutants of
RT cytochrome b reveals an interlaced splicing protein coded by an intron.";
RL Cell 22:333-348(1980).
RN [5]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 144-423, VARIANTS ASP-221; THR-315;
RP ALA-355 AND HIS-382, MUTAGENESIS OF VAL-364 AND ILE-393, AND FUNCTION.
RC STRAIN=Capensis / YB4237;
RX PubMed=8670880; DOI=10.1002/j.1460-2075.1996.tb00746.x;
RA Szczepanek T., Lazowska J.;
RT "Replacement of two non-adjacent amino acids in the S.cerevisiae bi2
RT intron-encoded RNA maturase is sufficient to gain a homing-endonuclease
RT activity.";
RL EMBO J. 15:3758-3767(1996).
RN [6]
RP MUTAGENESIS OF GLY-228; ASP-233; HIS-235; ILE-339; ASP-343; ASP-344;
RP SER-379 AND VAL-395, AND FUNCTION.
RX PubMed=11016843; DOI=10.1007/s004380000297;
RA Szczepanek T., Jamoussi K., Lazowska J.;
RT "Critical base substitutions that affect the splicing and/or homing
RT activities of the group I intron bi2 of yeast mitochondria.";
RL Mol. Gen. Genet. 264:137-144(2000).
CC -!- FUNCTION: This protein is responsible for splicing and maturation of
CC cytochrome b mRNA. Specifically, it may be responsible for the splicing
CC specificity of the second intron. {ECO:0000269|PubMed:11016843,
CC ECO:0000269|PubMed:7004642, ECO:0000269|PubMed:8670880}.
CC -!- SUBCELLULAR LOCATION: Mitochondrion inner membrane {ECO:0000305};
CC Multi-pass membrane protein {ECO:0000305}.
CC -!- POLYMORPHISM: The variant in strain Capensis / YB4237 has additional
CC DNA endonuclease (I-ScaI) activity promoting intron homing, which makes
CC intron 2 of the COB gene highly mobile (PubMed:8670880). Introduction
CC of 2 (Ala-355 and His-382) of its 4 variant residues into other strains
CC is sufficient for acquisition of endonuclease activity of the
CC corresponding mRNA maturases and for induction of intron mobility
CC (PubMed:8670880). {ECO:0000269|PubMed:8670880}.
CC -!- MISCELLANEOUS: Encoded from partially processed COB mRNA that
CC terminates with the in-frame coding sequence of the second intron.
CC -!- SIMILARITY: In the N-terminal section; belongs to the cytochrome b
CC family. {ECO:0000305}.
CC -!- SIMILARITY: In the C-terminal section; belongs to the LAGLIDADG
CC endonuclease family. {ECO:0000305}.
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DR EMBL; KP263414; AIZ98893.1; -; Genomic_DNA.
DR EMBL; V00696; CAA24073.2; ALT_SEQ; Genomic_DNA.
DR EMBL; J01472; AAA32150.2; -; Genomic_DNA.
DR EMBL; X95974; CAD24485.1; -; Genomic_DNA.
DR PIR; A04505; MRBY.
DR PIR; S78662; S78662.
DR RefSeq; NP_009318.1; NC_001224.1.
DR AlphaFoldDB; P03873; -.
DR SMR; P03873; -.
DR BioGRID; 34795; 6.
DR MINT; P03873; -.
DR STRING; 4932.Q0110; -.
DR REBASE; 2905; I-ScaI.
DR PaxDb; P03873; -.
DR PRIDE; P03873; -.
DR EnsemblFungi; Q0110_mRNA; Q0110; Q0110.
DR GeneID; 854604; -.
DR KEGG; sce:Q0110; -.
DR SGD; S000007271; BI2.
DR VEuPathDB; FungiDB:Q0110; -.
DR eggNOG; KOG4663; Eukaryota.
DR GeneTree; ENSGT00390000017948; -.
DR HOGENOM; CLU_649251_0_0_1; -.
DR InParanoid; P03873; -.
DR BioCyc; YEAST:G3O-34380-MON; -.
DR PRO; PR:P03873; -.
DR Proteomes; UP000002311; Mitochondrion.
DR RNAct; P03873; protein.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0005743; C:mitochondrial inner membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0005739; C:mitochondrion; TAS:SGD.
DR GO; GO:0009055; F:electron transfer activity; IEA:InterPro.
DR GO; GO:0004519; F:endonuclease activity; IEA:InterPro.
DR GO; GO:0004518; F:nuclease activity; IDA:SGD.
DR GO; GO:0006397; P:mRNA processing; IEA:UniProtKB-KW.
DR GO; GO:0022904; P:respiratory electron transport chain; IEA:InterPro.
DR GO; GO:0008380; P:RNA splicing; IDA:SGD.
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; PF03161; LAGLIDADG_2; 1.
DR SUPFAM; SSF55608; SSF55608; 1.
DR SUPFAM; SSF81342; SSF81342; 1.
DR PROSITE; PS51002; CYTB_NTER; 1.
PE 1: Evidence at protein level;
KW Membrane; Mitochondrion; Mitochondrion inner membrane; mRNA processing;
KW mRNA splicing; Reference proteome; Transmembrane; Transmembrane helix.
FT CHAIN 1..423
FT /note="Cytochrome b mRNA maturase bI2"
FT /id="PRO_0000061914"
FT TOPO_DOM 1..31
FT /note="Mitochondrial matrix"
FT /evidence="ECO:0000255"
FT TRANSMEM 32..52
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TOPO_DOM 53..84
FT /note="Mitochondrial intermembrane"
FT /evidence="ECO:0000255"
FT TRANSMEM 85..105
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TOPO_DOM 106..115
FT /note="Mitochondrial matrix"
FT /evidence="ECO:0000255"
FT TRANSMEM 116..136
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TOPO_DOM 137..153
FT /note="Mitochondrial intermembrane"
FT /evidence="ECO:0000255"
FT TRANSMEM 154..174
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TOPO_DOM 175..423
FT /note="Mitochondrial matrix"
FT /evidence="ECO:0000255"
FT REGION 1..143
FT /note="Cytochrome b"
FT REGION 144..423
FT /note="Maturase"
FT VARIANT 122
FT /note="I -> T (in strain: 777-3A)"
FT /evidence="ECO:0000269|PubMed:7004642"
FT VARIANT 221
FT /note="N -> D (in strain: Capensis / YB4237)"
FT /evidence="ECO:0000269|PubMed:8670880"
FT VARIANT 315
FT /note="M -> T (in strain: Capensis / YB4237)"
FT /evidence="ECO:0000269|PubMed:8670880"
FT VARIANT 324
FT /note="I -> M (in strain: 777-3A)"
FT /evidence="ECO:0000269|PubMed:7004642"
FT VARIANT 355
FT /note="T -> A (in strain: Capensis / YB4237)"
FT /evidence="ECO:0000269|PubMed:8670880"
FT VARIANT 382
FT /note="T -> H (in strain: Capensis / YB4237)"
FT /evidence="ECO:0000269|PubMed:8670880"
FT MUTAGEN 228
FT /note="G->D: In M1282 / M4111; abolishes maturase and
FT endonuclease activity."
FT /evidence="ECO:0000269|PubMed:11016843"
FT MUTAGEN 233
FT /note="D->S: Abolishes endonuclease activity."
FT /evidence="ECO:0000269|PubMed:11016843"
FT MUTAGEN 235
FT /note="H->P: In M4962; abolishes maturase and endonuclease
FT activity."
FT /evidence="ECO:0000269|PubMed:11016843"
FT MUTAGEN 339
FT /note="I->D: Abolishes maturase and endonuclease activity."
FT /evidence="ECO:0000269|PubMed:11016843"
FT MUTAGEN 343
FT /note="D->S: Abolishes endonuclease activity."
FT /evidence="ECO:0000269|PubMed:11016843"
FT MUTAGEN 344
FT /note="D->S: Abolishes endonuclease activity."
FT /evidence="ECO:0000269|PubMed:11016843"
FT MUTAGEN 364
FT /note="V->F: Abolishes endonuclease activity. In box3-2 /
FT G1909; abolishes maturase and endonuclease activity; when
FT associated with N-393."
FT /evidence="ECO:0000269|PubMed:7004642,
FT ECO:0000269|PubMed:8670880"
FT MUTAGEN 379
FT /note="S->Y: In W404-3; abolishes maturase and endonuclease
FT activity; when associated with M-395."
FT /evidence="ECO:0000269|PubMed:11016843"
FT MUTAGEN 393
FT /note="I->N: Abolishes endonuclease activity. In box3-2 /
FT G1909; abolishes maturase and endonuclease activity; when
FT associated with F-364."
FT /evidence="ECO:0000269|PubMed:7004642,
FT ECO:0000269|PubMed:8670880"
FT MUTAGEN 395
FT /note="V->M: In W404-4; abolishes maturase and endonuclease
FT activity; when associated with Y-379."
FT /evidence="ECO:0000269|PubMed:11016843"
SQ SEQUENCE 423 AA; 49326 MW; F9F9EE2F2C2CF7EE CRC64;
MAFRKSNVYL SLVNSYIIDS PQPSSINYWW NMGSLLGLCL VIQIVTGIFM AMHYSSNIEL
AFSSVEHIMR DVHNGYILRY LHANGASFFF MVMFMHMAKG LYYGSYRSPR VTLWNVGVII
FILTIATAFL GYCCVYGQMS HWGNMNIASN MFNMMKTIYM MMLMLLIYIF YTIMMRQMMK
TKEYTMLIKS MDYINKNKYM INLNMTNKKD MNNNIGPLNM NILSIIYGSM LGDGHAEKRK
GGKGTRIVFQ QEYCNINYLY YLHSLLANLG YCNTNLPLIK TRLGKKGKIR QYLKFNTWTY
DSFNMIYSEW YIKNMSGKGN IKVIPKSLDN YLTPLALAIW IMDDGCKLGK GLKFTTNCFS
YKDVQYLTYL LHNKYNIKST ITKGNKENTQ FVIYVWKESM PILTKIVSPY IIPSMKYKLG
NYL
