ID   TBB_POLAG               Reviewed;         443 AA.
AC   P22852;
DT   01-AUG-1991, integrated into UniProtKB/Swiss-Prot.
DT   01-AUG-1991, sequence version 1.
DT   03-AUG-2022, entry version 102.
DE   RecName: Full=Tubulin beta chain;
DE   AltName: Full=Beta-tubulin;
GN   Name=TUBB1;
GN   and
GN   Name=TUBB2;
GN   and
GN   Name=TUBB3;
OS   Polytomella agilis (Quadriflagellate alga).
OC   Eukaryota; Viridiplantae; Chlorophyta; core chlorophytes; Chlorophyceae;
OC   CS clade; Chlamydomonadales; Chlamydomonadaceae; Polytomella.
OX   NCBI_TaxID=3050;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=2533130; DOI=10.1016/0378-1119(89)90509-x;
RA   Conner T.W., Thompson M.D., Silflow C.D.;
RT   "Structure of the three beta-tubulin-encoding genes of the unicellular
RT   alga, Polytomella agilis.";
RL   Gene 84:345-358(1989).
CC   -!- FUNCTION: Tubulin is the major constituent of microtubules. It binds
CC       two moles of GTP, one at an exchangeable site on the beta chain and one
CC       at a non-exchangeable site on the alpha chain.
CC   -!- SUBUNIT: Dimer of alpha and beta chains. A typical microtubule is a
CC       hollow water-filled tube with an outer diameter of 25 nm and an inner
CC       diameter of 15 nM. Alpha-beta heterodimers associate head-to-tail to
CC       form protofilaments running lengthwise along the microtubule wall with
CC       the beta-tubulin subunit facing the microtubule plus end conferring a
CC       structural polarity. Microtubules usually have 13 protofilaments but
CC       different protofilament numbers can be found in some organisms and
CC       specialized cells.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm, cytoskeleton.
CC   -!- MISCELLANEOUS: The sequences of the three genes coding for beta-tubulin
CC       are identical.
CC   -!- SIMILARITY: Belongs to the tubulin family. {ECO:0000305}.
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DR   EMBL; M33372; AAB03892.1; -; Genomic_DNA.
DR   EMBL; M33373; AAA33803.1; -; Genomic_DNA.
DR   EMBL; M33371; AAA33804.1; -; Genomic_DNA.
DR   PIR; JQ0177; JQ0177.
DR   PIR; MZ0005; MZ0005.
DR   AlphaFoldDB; P22852; -.
DR   SMR; P22852; -.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-KW.
DR   GO; GO:0005874; C:microtubule; IEA:UniProtKB-KW.
DR   GO; GO:0005525; F:GTP binding; IEA:UniProtKB-KW.
DR   GO; GO:0005200; F:structural constituent of cytoskeleton; IEA:InterPro.
DR   GO; GO:0007017; P:microtubule-based process; IEA:InterPro.
DR   Gene3D; 1.10.287.600; -; 1.
DR   Gene3D; 3.30.1330.20; -; 1.
DR   Gene3D; 3.40.50.1440; -; 1.
DR   InterPro; IPR013838; Beta-tubulin_BS.
DR   InterPro; IPR002453; Beta_tubulin.
DR   InterPro; IPR008280; Tub_FtsZ_C.
DR   InterPro; IPR000217; Tubulin.
DR   InterPro; IPR037103; Tubulin/FtsZ-like_C.
DR   InterPro; IPR018316; Tubulin/FtsZ_2-layer-sand-dom.
DR   InterPro; IPR036525; Tubulin/FtsZ_GTPase_sf.
DR   InterPro; IPR023123; Tubulin_C.
DR   InterPro; IPR017975; Tubulin_CS.
DR   InterPro; IPR003008; Tubulin_FtsZ_GTPase.
DR   PANTHER; PTHR11588; PTHR11588; 1.
DR   Pfam; PF00091; Tubulin; 1.
DR   Pfam; PF03953; Tubulin_C; 1.
DR   PRINTS; PR01163; BETATUBULIN.
DR   PRINTS; PR01161; TUBULIN.
DR   SMART; SM00864; Tubulin; 1.
DR   SMART; SM00865; Tubulin_C; 1.
DR   SUPFAM; SSF52490; SSF52490; 1.
DR   SUPFAM; SSF55307; SSF55307; 1.
DR   PROSITE; PS00227; TUBULIN; 1.
DR   PROSITE; PS00228; TUBULIN_B_AUTOREG; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; Cytoskeleton; GTP-binding; Microtubule; Nucleotide-binding.
FT   CHAIN           1..443
FT                   /note="Tubulin beta chain"
FT                   /id="PRO_0000048374"
FT   REGION          421..443
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   BINDING         140..146
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000255"
FT   CONFLICT        37
FT                   /note="L -> I (in Ref. 1; AAA33803)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   443 AA;  49576 MW;  FFD95FF59E5C4EA3 CRC64;
     MREIVHIQGG QCGNQIGAKF WEVVSDEHGI DPTGTALGDS DLQLERINVY FNEATGSRYV
     PRAILMDLEP GTMDSVRSGP YGQIFRPDNF VFGQTGAGNN WAKGHYTEGA ELIDSVLDVV
     RKEAESCDCL QGFQVCHSLG GGTGSGMGTL LISKIREEYP DRMMLTFSVV PSPKVSDTVV
     EPYNATLSVH QLVENADECM VLDNEALYDI CFRTLKLTTP TFGDLNHLIS AVMSGITCCL
     RFPGQLNADL RKLAVNLIPF PRLHFFMVGF TPLTSRGSQQ YRALTVPELT QQMWDAKNMM
     CAADPRHGRY LTASALFRGR MSTKEVDEQM LNVQNKNSSY FVEWIPNNVK SSVCDIPPKG
     LKMSATFIGN STAIQEMFKR VSEQFTAMFR RKAFLHWYTG EGMDEMEFTE AESNMNDLVS
     EYQQYQDASA EEEGEFGEEE EEN