ID   B2_USTMD                Reviewed;         410 AA.
AC   P22016;
DT   01-AUG-1991, integrated into UniProtKB/Swiss-Prot.
DT   01-AUG-1991, sequence version 1.
DT   25-MAY-2022, entry version 87.
DE   RecName: Full=Mating-type locus allele B2 protein;
OS   Ustilago maydis (Corn smut fungus).
OC   Eukaryota; Fungi; Dikarya; Basidiomycota; Ustilaginomycotina;
OC   Ustilaginomycetes; Ustilaginales; Ustilaginaceae; Ustilago.
OX   NCBI_TaxID=5270;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=518;
RX   PubMed=1967554; DOI=10.1016/0092-8674(90)90744-y;
RA   Schulz B., Banuett F., Dahl M., Schlesinger R., Schaefer W., Martin T.,
RA   Herskowitz I., Kahmann R.;
RT   "The b alleles of U. maydis, whose combinations program pathogenic
RT   development, code for polypeptides containing a homeodomain-related
RT   motif.";
RL   Cell 60:295-306(1990).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=518;
RX   PubMed=2227416; DOI=10.1101/gad.4.8.1384;
RA   Kronstad J.W., Leong S.A.;
RT   "The b mating-type locus of Ustilago maydis contains variable and constant
RT   regions.";
RL   Genes Dev. 4:1384-1395(1990).
CC   -!- FUNCTION: The B locus has at least 25 alleles, and any combination of
CC       two different B alleles yields a multimeric regulatory protein, that
CC       activates genes responsible for the pathogenicity and for the sexual
CC       development of the fungus within the corn plant.
CC   -!- SUBCELLULAR LOCATION: Nucleus.
CC   -!- SIMILARITY: Belongs to the TALE/M-ATYP homeobox family. {ECO:0000305}.
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DR   EMBL; M58554; AAA63554.1; -; Genomic_DNA.
DR   PIR; B36671; B32696.
DR   AlphaFoldDB; P22016; -.
DR   SMR; P22016; -.
DR   VEuPathDB; FungiDB:UMAG_12052; -.
DR   GO; GO:0005634; C:nucleus; IEA:UniProtKB-SubCell.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0006355; P:regulation of transcription, DNA-templated; IEA:InterPro.
DR   CDD; cd00086; homeodomain; 1.
DR   InterPro; IPR009057; Homeobox-like_sf.
DR   InterPro; IPR001356; Homeobox_dom.
DR   InterPro; IPR008422; Homeobox_KN_domain.
DR   InterPro; IPR008888; Ustilago_mating.
DR   Pfam; PF05920; Homeobox_KN; 1.
DR   Pfam; PF05722; Ustilago_mating; 1.
DR   SUPFAM; SSF46689; SSF46689; 1.
DR   PROSITE; PS50071; HOMEOBOX_2; 1.
PE   3: Inferred from homology;
KW   DNA-binding; Homeobox; Nucleus.
FT   CHAIN           1..410
FT                   /note="Mating-type locus allele B2 protein"
FT                   /id="PRO_0000049402"
FT   DNA_BIND        107..184
FT                   /note="Homeobox; TALE-type"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00108"
FT   REGION          1..110
FT                   /note="Variable domain between B alleles"
FT   REGION          111..410
FT                   /note="Highly conserved between B alleles"
FT   REGION          201..239
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          278..335
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          333..410
FT                   /note="Not essential for B2 function"
FT   REGION          374..395
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   MOTIF           276..308
FT                   /note="Nuclear localization signal"
FT                   /evidence="ECO:0000255"
FT   COMPBIAS        202..229
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        309..335
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   410 AA;  45957 MW;  87EC0E270C8C9216 CRC64;
     MSNYPNFSLT SFVECLNEIE HEFLRDKLEN RPVLVRKLQE LRRKTPNNVA SLSYDPGTIH
     QIHQTTHRIK VAAKAFIRID QSFVSLHSDA VEDTSKALKK ADASSPVVGC RDLSEDLPAY
     HMRKHFLHTL DNPYPTQEEK EGLVRLTNES TARVGLSKAN RPPLEVHQLT LWFINARRRS
     GWSHILKKFA REDRSRMKHL VRAKLSSSNQ STPPSSTSDS LSNNLDDVLS DNLGRPLTPV
     DKQQFEDDWA SMISWIKYGV KEKVGDWVYD LCAASKKTPK PGMPRPVTTV AKRHPARKTK
     PAAKPKSRTA NPRASTTPSI DSTLDSSKLE STPELSMCST ADTSFSTFGS SLSMSHYNPF
     QDGNDILQSP TVKARGNRKV KALPKRAGKQ QPDEVENGKI PFLCLSVAFV