ID   TBB8_ARATH              Reviewed;         449 AA.
AC   P29516; Q93Y15; Q9FF94;
DT   01-APR-1993, integrated into UniProtKB/Swiss-Prot.
DT   10-JAN-2003, sequence version 2.
DT   02-SEP-2026, entry version 179.
DE   RecName: Full=Tubulin beta-8 chain;
DE   AltName: Full=Beta-8-tubulin;
GN   Name=TUBB8; Synonyms=TUB8; OrderedLocusNames=At5g23860;
GN   ORFNames=MRO11.10;
OS   Arabidopsis thaliana (Mouse-ear cress).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   rosids; malvids; Brassicales; Brassicaceae; Camelineae; Arabidopsis.
OX   NCBI_TaxID=3702;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=cv. Columbia;
RX   PubMed=1498609; DOI=10.1105/tpc.4.5.549;
RA   Snustad D.P., Haas N.A., Kopczak S.D., Silflow C.D.;
RT   "The small genome of Arabidopsis contains at least nine expressed beta-
RT   tubulin genes.";
RL   Plant Cell 4:549-556(1992).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=cv. Columbia;
RX   PubMed=9330910; DOI=10.1093/dnares/4.3.215;
RA   Sato S., Kotani H., Nakamura Y., Kaneko T., Asamizu E., Fukami M.,
RA   Miyajima N., Tabata S.;
RT   "Structural analysis of Arabidopsis thaliana chromosome 5. I. Sequence
RT   features of the 1.6 Mb regions covered by twenty physically assigned P1
RT   clones.";
RL   DNA Res. 4:215-230(1997).
RN   [3]
RP   GENOME REANNOTATION.
RC   STRAIN=cv. Columbia;
RX   PubMed=27862469; DOI=10.1111/tpj.13415;
RA   Cheng C.Y., Krishnakumar V., Chan A.P., Thibaud-Nissen F., Schobel S.,
RA   Town C.D.;
RT   "Araport11: a complete reannotation of the Arabidopsis thaliana reference
RT   genome.";
RL   Plant J. 89:789-804(2017).
RN   [4]
RP   GENOME REANNOTATION.
RC   STRAIN=cv. Columbia;
RG   The Arabidopsis Information Resource (TAIR);
RT   "Community-consensus reference genome of Arabidopsis thaliana Col-0.";
RL   Submitted (FEB-2026) to the EMBL/GenBank/DDBJ databases.
RN   [5]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   STRAIN=cv. Columbia;
RX   PubMed=14593172; DOI=10.1126/science.1088305;
RA   Yamada K., Lim J., Dale J.M., Chen H., Shinn P., Palm C.J., Southwick A.M.,
RA   Wu H.C., Kim C.J., Nguyen M., Pham P.K., Cheuk R.F., Karlin-Newmann G.,
RA   Liu S.X., Lam B., Sakano H., Wu T., Yu G., Miranda M., Quach H.L.,
RA   Tripp M., Chang C.H., Lee J.M., Toriumi M.J., Chan M.M., Tang C.C.,
RA   Onodera C.S., Deng J.M., Akiyama K., Ansari Y., Arakawa T., Banh J.,
RA   Banno F., Bowser L., Brooks S.Y., Carninci P., Chao Q., Choy N., Enju A.,
RA   Goldsmith A.D., Gurjal M., Hansen N.F., Hayashizaki Y., Johnson-Hopson C.,
RA   Hsuan V.W., Iida K., Karnes M., Khan S., Koesema E., Ishida J., Jiang P.X.,
RA   Jones T., Kawai J., Kamiya A., Meyers C., Nakajima M., Narusaka M.,
RA   Seki M., Sakurai T., Satou M., Tamse R., Vaysberg M., Wallender E.K.,
RA   Wong C., Yamamura Y., Yuan S., Shinozaki K., Davis R.W., Theologis A.,
RA   Ecker J.R.;
RT   "Empirical analysis of transcriptional activity in the Arabidopsis
RT   genome.";
RL   Science 302:842-846(2003).
CC   -!- FUNCTION: Tubulin is the major constituent of microtubules, a cylinder
CC       consisting of laterally associated linear protofilaments composed of
CC       alpha- and beta-tubulin heterodimers. Microtubules grow by the addition
CC       of GTP-tubulin dimers to the microtubule end, where a stabilizing cap
CC       forms. Below the cap, tubulin dimers are in GDP-bound state, owing to
CC       GTPase activity of alpha-tubulin.
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC         Evidence={ECO:0000250|UniProtKB:P68363};
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: There are nine genes coding for beta-tubulin.
CC   -!- SIMILARITY: Belongs to the tubulin family. {ECO:0000305}.
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DR   EMBL; M84705; AAA32886.1; -; Genomic_DNA.
DR   EMBL; AB005244; BAB10059.1; -; Genomic_DNA.
DR   EMBL; CP002688; AED93223.1; -; Genomic_DNA.
DR   EMBL; CP002688; AED93224.1; -; Genomic_DNA.
DR   EMBL; OZ408687; CAO7053314.1; -; Genomic_DNA.
DR   EMBL; AY054693; AAK96884.1; -; mRNA.
DR   EMBL; AY081473; AAM10035.1; -; mRNA.
DR   PIR; JQ1592; JQ1592.
DR   RefSeq; NP_001190373.1; NM_001203444.1.
DR   RefSeq; NP_568437.1; NM_122291.4.
DR   AlphaFoldDB; P29516; -.
DR   SMR; P29516; -.
DR   BioGRID; 17726; 8.
DR   FunCoup; P29516; 2077.
DR   IntAct; P29516; 2.
DR   STRING; 3702.P29516; -.
DR   MetOSite; P29516; -.
DR   PaxDb; 3702-P29516; -.
DR   ProteomicsDB; 234183; -.
DR   GeneID; 832451; -.
DR   KEGG; ath:AT5G23860; -.
DR   Araport; AT5G23860; -.
DR   TAIR; AT5G23860; TUB8.
DR   eggNOG; KOG1375; Eukaryota.
DR   HOGENOM; CLU_015718_1_1_1; -.
DR   InParanoid; P29516; -.
DR   OMA; WVPRSVN; -.
DR   OrthoDB; 1662883at2759; -.
DR   PhylomeDB; P29516; -.
DR   PRO; PR:P29516; -.
DR   Proteomes; UP000006548; Chromosome 5.
DR   ExpressionAtlas; P29516; baseline and differential.
DR   GO; GO:0005737; C:cytoplasm; ISM:TAIR.
DR   GO; GO:0005829; C:cytosol; HDA:TAIR.
DR   GO; GO:0005794; C:Golgi apparatus; HDA:TAIR.
DR   GO; GO:0005874; C:microtubule; IEA:InterPro.
DR   GO; GO:0045298; C:tubulin complex; ISS:TAIR.
DR   GO; GO:0005525; F:GTP binding; IBA:GO_Central.
DR   GO; GO:0003924; F:GTPase activity; IEA:InterPro.
DR   GO; GO:0003729; F:mRNA binding; IDA:TAIR.
DR   GO; GO:0005200; F:structural constituent of cytoskeleton; ISS:TAIR.
DR   GO; GO:0007017; P:microtubule-based process; ISS:TAIR.
DR   GO; GO:0000278; P:mitotic cell cycle; IBA:GO_Central.
DR   CDD; cd02187; beta_tubulin; 1.
DR   FunFam; 1.10.287.600:FF:000002; Tubulin beta chain; 1.
DR   FunFam; 3.30.1330.20:FF:000002; Tubulin beta chain; 1.
DR   FunFam; 3.40.50.1440:FF:000005; Tubulin beta chain; 1.
DR   Gene3D; 1.10.287.600; Helix hairpin bin; 1.
DR   Gene3D; 3.30.1330.20; Tubulin/FtsZ, C-terminal domain; 1.
DR   Gene3D; 3.40.50.1440; Tubulin/FtsZ, GTPase domain; 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; TUBULIN; 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; SSF55307; Tubulin C-terminal domain-like; 1.
DR   SUPFAM; SSF52490; Tubulin nucleotide-binding domain-like; 1.
DR   PROSITE; PS00227; TUBULIN; 1.
DR   PROSITE; PS00228; TUBULIN_B_AUTOREG; 1.
PE   2: Evidence at transcript level;
KW   Cytoplasm; Cytoskeleton; GTP-binding; Magnesium; Metal-binding;
KW   Microtubule; Nucleotide-binding; Reference proteome.
FT   CHAIN           1..449
FT                   /note="Tubulin beta-8 chain"
FT                   /id="PRO_0000048327"
FT   REGION          428..449
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        429..449
FT                   /note="Acidic residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   BINDING         11
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250|UniProtKB:Q13509"
FT   BINDING         69
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250|UniProtKB:P68363"
FT   BINDING         69
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250|UniProtKB:P68363"
FT   BINDING         138
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250|UniProtKB:Q13509"
FT   BINDING         142
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250|UniProtKB:Q13509"
FT   BINDING         143
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250|UniProtKB:Q13509"
FT   BINDING         144
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250|UniProtKB:Q13509"
FT   BINDING         204
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250|UniProtKB:Q13509"
FT   BINDING         226
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250|UniProtKB:Q13509"
FT   CONFLICT        40
FT                   /note="N -> K (in Ref. 5; AAM10035/AAK96884)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        124
FT                   /note="A -> R (in Ref. 1; AAA32886)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        164..165
FT                   /note="ML -> IV (in Ref. 1; AAA32886)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        170
FT                   /note="F -> I (in Ref. 1; AAA32886)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   449 AA;  50607 MW;  C66EBE7C8FB18F05 CRC64;
     MREILHIQGG QCGNQIGAKF WEVVCAEHGI DSTGRYQGEN DLQLERVNVY YNEASCGRFV
     PRAVLMDLEP GTMDSVRSGP YGQIFRPDNF VFGQSGAGNN WAKGHYTEGA ELIDSVLDVV
     RKEAENCDCL QGFQVCHSLG GGTGSGMGTL LISKIREEYP DRMMLTFSVF PSPKVSDTVV
     EPYNATLSVH QLVENADECM VLDNEALYDI CFRTLKLTTP SFGDLNHLIS ATMSGVTCCL
     RFPGQLNSDL RKLAVNLIPF PRLHFFMVGF APLTSRGSQQ YRALTVPELT QQMWDAKNMM
     CAADPRHGRY LTASAMFRGK MSTKEVDEQM INVQNKNSSY FVEWIPNNVK STVCDIPPTG
     LKMASTFIGN STSIQEMFRR VSEQFTAMFR RKAFLHWYTG EGMDEMEFTE AESNMNDLVS
     EYQQYQDATA DEEEGYEYEE DEVEVQEEQ
//